Mapping Mountains – Summit Relocations – Y Trichant - The 300m Hills of Wales

Y Trichant – The 300m Hills of Wales – Summit Relocations

Y Trichant - The 300m Hills of Wales are all Welsh hills at and above 300m and below 40om in height that have 30m minimum drop.  These hills form the 300m height band within the listing of the Twmpau (thirty welsh metre prominences and upward).  Accompanying the main P30 list is a sub list entitled the 300m Sub-Trichant with qualification to this sub category being all Welsh hills at and above 300m and below 400m in height with 20m or more and below 30m of drop, with the Introduction to this list giving its publication history appearing on Mapping Mountains on 13.05.17.

The list is authored by Myrddyn Phillips and the posts that have appeared on Mapping Mountains detailing the summit relocations to the main P30 list and the sub list appear below presented chronologically in receding order.

Mapping Mountains - Summit Relocations - Y Trichant

Allt yr Hafod (SN 668 442) - 35th summit relocation

Significant Name Changes post for Allt yr Hafod

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data and LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Allt yr Hafod (SN 668 442)

The criteria for the list that this summit relocation applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Allt yr Hafod, and it is adjoined to the Esgair Wen group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its north, west and south-east and the A482 road to its south-west, and has the town of Llanbedr Pont Steffan (Lampeter) towards the west north-west.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list with a summit height of 311m, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map and which is positioned at SN 66875 44216. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR analysis gives the highest ground on this hill as 310.3m positioned at SN 66863 44189.  However, this is a part of a raised field boundary and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill. 

LIDAR summit image of Allt yr Hafod (SN 668 442)

LIDAR close up summit image of Allt yr Hafod (SN 668 442)

The height produced by LIDAR analysis to the natural summit of this hill is 310.2m positioned at SN 66859 44201, and this position in relation to the raised field boundary comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 310.2m and this is positioned at SN 66859 44201, this position is close to where the 311m spot height appears on the contemporary Ordnance Survey 1:25,000 Explorer map, and is approximately 12 metres northward from where the high point of the raised field boundary is positioned. 

 

The full details for the hill are:

Group:  Esgair Wen 

Name:  Allt yr Hafod 

OS 1:50,000 map:  146

Summit Height:  310.2m (LIDAR)                                                           

Summit Grid Reference (New Position):  SN 66859 44201 (LIDAR) 

Bwlch Height:  c 288m (interpolation) 

Bwlch Grid Reference:  SN 67104 44293 (interpolation) 

Drop:  c 22m (LIDAR summit and interpolated bwlch) 

 

Myrddyn Phillips (April 2023)

Mapping Mountains - Summit Relocations - Y Trichant

Lan Ystenu (SN 960 532) - 34th summit relocation

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Lan Ystenu (SN 960 532)

The criteria for the list that this summit relocation applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Lan Ystenu, and it is adjoined to the Drygarn Fawr group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B1), and it is positioned with the B4358 road to its north-west, minor roads to its south-west and east, and the A483 road farther to its south, and has the village of Beulah towards the west south-west.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a summit height of 331m, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map and which is positioned at SN 961 530. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Lan Ystenu (SN 960 532)

The summit height produced by LIDAR analysis is 329.9m positioned at SN 96089 53229, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 329.9m and this is positioned at SN 96089 53229, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 210 metres northward from where the originally listed summit is positioned. 

 

The full details for the hill are:

Group:  Drygarn Fawr 

Name:  Lan Ystenu 

OS 1:50,000 map:  147

Summit Height:  329.9m (LIDAR)                                                           

Summit Grid Reference (New Position):  SN 96089 53229 (LIDAR) 

Bwlch Height:  271.2m (LIDAR) 

Bwlch Grid Reference:  SN 95950 53655 (LIDAR) 

Drop:  58.7m (LIDAR) 

 

Myrddyn Phillips (March 2023)

Mapping Mountains - Summit Relocations - Y Trichant

Cefn Isaf (SN 800 486) - 33rd summit relocation

Significant Height Revisions post for Cefn Isaf

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cefn Isaf (SN 800 486)

The criteria for the list that this summit relocation applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Cefn Isaf, and it is adjoined to the Drygarn Fawr group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B1), and it is positioned with a minor road to its south-east and the A483 road farther to its south-east, and has the town of Llanwrtyd (Llanwrtyd Wells) towards the east south-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a summit height of 388m, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map and which is positioned at SN 801 487. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Cefn Isaf (SN 800 486)

The summit height produced by LIDAR analysis is 386.0m positioned at SN 80031 48623, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 386.0m and this is positioned at SN 80031 48623, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 105 metres south-westward from where the originally listed summit is positioned. 

 

The full details for the hill are:

Group:  Drygarn Fawr 

Name:  Cefn Isaf 

OS 1:50,000 map:  147

Summit Height:  386.0m (LIDAR)                                                           

Summit Grid Reference (New Position):  SN 80031 48623 (LIDAR) 

Bwlch Height:  345.5m (LIDAR) 

Bwlch Grid Reference:  SN 80361 48591 (LIDAR) 

Drop:  40.5m (LIDAR) 

 

Myrddyn Phillips (March 2023)

 

Mapping Mountains - Summit Relocations - Y Trichant

Graig Orddle (SN 998 935) - 32nd summit relocation

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Graig Orddle (SN 998 935)

The criteria for the list that this summit relocation applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Graig Orddle, and it is adjoined to the Pumlumon group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B1), and it is positioned with the A470 road to its north-east, a minor road to its west and the B4569 to its south, and has the village of Caersŵs towards the south-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included under the name of Foel y Belan with a 352m summit height, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map and which is positioned at SN 994 933. 

Extract from the Ordnance Survey 1:25,000 Explorer map

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and for this hill it had a twin 352m spot heighted summit named Graig Orddle and which is positioned at SN 998 935.

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR image of Foel y Belan (SN 994 933) and Graig Orddle (SN 998 935)

The summit height produced by LIDAR analysis for Graig Orddle is 351.8m positioned at SN 99841 93587, whilst the summit height produced by LIDAR analysis for Foel y Belan is 351.3m positioned at SN 99411 93331, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 351.8m and this is positioned at SN 99841 93587, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 500 metres north-eastward from where the originally listed summit is positioned. 

 

The full details for the hill are:

Group:  Pumlumon 

Name:  Graig Orddle 

OS 1:50,000 map:  136

Summit Height:  351.8m (LIDAR)                                                           

Summit Grid Reference:  SN 99841 93587 (LIDAR) 

Bwlch Height:  272.8m (LIDAR) 

Bwlch Grid Reference:  SN 98777 93951 (LIDAR) 

Drop:  79.0m (LIDAR) 

 

Myrddyn Phillips (November 2022)

Mapping Mountains - Summit Relocations - Y Trichant

Mynydd Llanfair (SJ 038 040) - 31st summit relocation

Hill Reclassifications post for Mynydd Llanfair

Significant Name Changes post for Mynydd Llanfair

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Mynydd Llanfair (SJ 038 040)

The criteria for the list that this summit relocation applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Mynydd Llanfair and this was derived from the Tithe map, and it is adjoined to the Carnedd Wen group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned with the A458 road to its north, a minor road to its south and the A470 road to its south-west, and has the small town of Llanfair Caereinion towards the east north-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category.

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 21m of drop, based on the 374m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and which is positioned at SJ 03817 04112, and an estimated c 353m bwlch height, based on interpolation of 5m contouring between 350m – 355m. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Mynydd Llanfair (SJ 038 040)

The summit height produced by LIDAR analysis is 373.7m positioned at SJ 03809 04011, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 373.7m and this is positioned at SJ 03809 04011, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 100 metres southward from where the previously listed summit is positioned. 

 

The full details for the hill are:

Group:  Carnedd Wen 

Name:  Mynydd Llanfair 

OS 1:50,000 map:  136

Summit Height:  373.7m (LIDAR)                                                           

Summit Grid Reference:  SJ 03809 04011 (LIDAR) 

Bwlch Height:  351.9m (LIDAR) 

Bwlch Grid Reference:  SJ 03291 04027 (LIDAR) 

Drop:  21.8m (LIDAR) 

 

Myrddyn Phillips (October 2022)

Mapping Mountains - Summit Relocations - Y Trichant

Cefn Gwyn (SO 028 995) - 30th summit relocation

Hill Reclassifications post for Cefn Gwyn

Significant Name Changes post for Cefn Gwyn

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cefn Gwyn (SO 028 995)

The criteria for the list that this summit relocation applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Cefn Gwyn, and it is adjoined to the Carnedd Wen group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned with minor roads to its north, west and east, and the A470 road to its south-west, and has the village of Caersŵs towards the south.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category.

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with 21m of drop, based on the 382m summit spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was positioned at SO 02796 99670, and the 361m bwlch spot height that appears on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Cefn Gwyn (SO 028 995)

The summit height produced by LIDAR analysis is 382.7m and is positioned at SO 02813 99573, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 382.7m and this is positioned at SO 02813 99573, this position is not given a spot height on the contemporary Ordnance Survey 1:25,000 Explorer map, and is approximately 100 metres southward from where the previously listed summit was given. 

 

The full details for the hill are:

Group:  Carnedd Wen 

Name:  Cefn Gwyn 

OS 1:50,000 map:  136

Summit Height:  382.7m (LIDAR)                                                           

Summit Grid Reference (New Position):  SO 02813 99573 (LIDAR) 

Bwlch Height:  362.0m (LIDAR) 

Bwlch Grid Reference:  SO 02633 99303 (LIDAR) 

Drop:  20.6m (LIDAR) 

 

Myrddyn Phillips (October 2022)

Mapping Mountains - Summit Relocations - Y Trichant

Pt. 333.2m (SJ 091 161) - 29th summit relocation

Significant Name Changes post for Pt. 333.2m

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their location, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Pt. 333.2m (SJ 091 161)

The criteria for the list that this summit relocation applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The hill is being listed by the point (Pt. 333.2m) notation as an appropriate name for it either through local enquiry and/or historic research has not been found by the author, and it is adjoined to the Foel Cedig group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned with minor roads to its north, west and south, the B4393 road farther to its north and the B4382 road farther to its west, and has the town of Llanfyllin towards the north-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was listed with a summit height of 331m based on the spot height that appears on the Ordnance Survey 1:50,000 Landranger map which is positioned at SJ 091 161. 

Extract from the Ordnance Survey 1:50,000 Landranger map

Since publication of the P30 lists on Geoff Crowder’s v-g.me website there have been a number of Ordnance Survey maps made available online, some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website, whilst others are current and digitally updated such as the old Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map and the interactive mapping available on the Magic Maps and WalkLakes websites.

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available maps and for this hill it had two 333m summit spot heights positioned at SJ 09191 16163 and SJ 09211 16296, with the prioritised summit relocated to the latter position.

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Pt. 333.2m (SJ 091 161)

The summit height produced by LIDAR analysis is 333.2m and is positioned at SJ 09191 16165, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 333.2m and this is positioned at SJ 09191 16165, this position is not given a spot height on the contemporary Ordnance Survey 1:25,000 Explorer map, and is approximately 130 metres southward from where the previously listed priority summit was given. 

 

The full details for the hill are:

Group:  Foel Cedig 

Name:  Pt. 333.2m 

OS 1:50,000 map:  125

Summit Height:  333.2m (LIDAR)                                                           

Summit Grid Reference (New Position):  SJ 09191 16165 (LIDAR) 

Bwlch Height:  305.3m (LIDAR) 

Bwlch Grid Reference:  SJ 09266 16570 (LIDAR) 

Drop:  27.8m (LIDAR) 

 

Myrddyn Phillips (August 2022)

Mapping Mountains - Summit Relocations - Y Trichant

Banc Cwm Coed Ifor (SN 594 385) - 28th summit relocation

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales and Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height and their locations, the drop, dominance and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Banc Cwm Coed Ifor (SN 594 385)

The criteria for the two listings that this summit relocation applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

Y Trechol – The Dominant Hills of Wales – Welsh P30 hills whose prominence equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015, and the list is now available in its entirety on Mapping Mountains in Google Doc format. 

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Banc Cwm Coed Ifor, and it is adjoined to the Mynydd Pencarreg group of hills, which are situated in the south-western part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its north, north-west and east, and the B4337 road to its south-west, and has the village of Llansawel towards the south-east.

When the original Welsh 300m P30 list was published on Geoff Crowder’s v-g.me website, this hill was listed with a 309m summit height, based on the spot height that is positioned at SN 59256 38502 and appears on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Banc Cwm Coed Ifor (SN 594 385)

The summit height produced by LIDAR analysis is 308.1m and is positioned at SN 59407 38541, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 308.1m and is positioned at SN 59407 38541, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 150 metres eastward from where the previously listed summit is positioned. 

 

The full details for the hill are: 

Group:  Mynydd Pencarreg 

Name:  Banc Cwm Coed Ifor 

OS 1:50,000 map:  146

Summit Height:  308.1m (LIDAR) 

Summit Grid Reference (New Position):  SN 59407 38541 (LIDAR) 

Bwlch Height:  196.6m (LIDAR) 

Bwlch Grid Reference:  SN 58001 39509 (LIDAR) 

Drop:  111.5m (LIDAR) 

Dominance:  36.19% (LIDAR) 

 

Myrddyn Phillips (June 2022)

Mapping Mountains - Summit Relocations - Y Trichant

Lan Ddu Cilwenau (SN 572 371) - 27th summit reloocation

Significant Height Revisions post for Lan Ddu Cilwenau

Significant Name Changes post for Lan Ddu Cilwenau

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales and Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height and their locations, the drop, dominance and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data and LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Lan Ddu Cilwenau (SN 572 371)

The criteria for the two listings that this summit relocation applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

Y Trechol – The Dominant Hills of Wales – Welsh P30 hills whose prominence equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015, and the list is now available in its entirety on Mapping Mountains in Google Doc format. 

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Lan Ddu Cilwenau, and it is adjoined to the Mynydd Pencarreg group of hills, which are situated in the south-western part of South Wales (Region B, Sub-Region B1), and it is positioned with the B4337 road to its north-east, a minor road to its south-west and the B4310 road to its south-east, and has the village of Llansawel towards the east south-east.

When the original Welsh 300m P30 list was published on Geoff Crowder’s v-g.me website, this hill was listed with a 328m summit height, based on the spot height that is positioned at SN 57642 37049 and appears on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Lan Ddu Cilwenau (SN 572 371)

The summit height produced by LIDAR analysis is 333.1m and is positioned at SN 57277 37147, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 333.1m and is positioned at SN 57277 37147, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 400 metres eastward from where the previously listed summit is positioned. 

 

The full details for the hill are: 

Group:  Mynydd Pencarreg 

Name:  Lan Ddu Cilwenau 

OS 1:50,000 map:  146

Summit Height:  333.1m (LIDAR) 

Summit Grid Reference (New Position):  SN 57277 37147 (LIDAR) 

Bwlch Height:  c 211m (interpolation) 

Bwlch Grid Reference:  SN 56467 37617 (interpolation) 

Drop:  c 122m (LIDAR summit and interpolated bwlch) 

Dominance:  36.66% (LIDAR summit and interpolated bwlch) 

 

Myrddyn Phillips (May 2022)

 

Mapping Mountains - Summit Relocations - Y Trichant

Mynydd Cefn Ddwy Graig (SH 936 340) - 26th summit relocation

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their location, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Mynydd Cefn Ddwy Graig (SH 936 340)

The criteria for the list that this summit relocation applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Mynydd Cefn Ddwy Graig, and it is adjoined to the Esgeiriau Gwynion group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned with the B4391 road to its north, the B4403 road to its west and a minor road to its south, and has the town of Y Bala towards the north north-west.

When the sub list was standardised and interpolated heights and drop values also included in the original Welsh 300m P30 list that was published on Geoff Crowder’s v-g.me website, this hill was listed with an estimated c 348m summit height positioned at SH 933 339, based on interpolation of its uppermost 340m ring contour. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Mynydd Cefn Ddwy Graig (SH 936 340)

The summit height produced by LIDAR analysis is 346.4m and is positioned at SH 93620 34020, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 346.4m and this is positioned at SH 93620 34020, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 260 metres eastward from where the previously listed summit was given. 

 

The full details for the hill are:

Group:  Esgeiriau Gwynion 

Name:  Mynydd Cefn Ddwy Graig 

OS 1:50,000 map:  125

Summit Height:  346.4m (LIDAR)                                                           

Summit Grid Reference (New Position):  SH 93620 34020 (LIDAR) 

Bwlch Height:  317.8m (LIDAR) 

Bwlch Grid Reference:  SH 93117 33669 (LIDAR) 

Drop:  28.55m (LIDAR) 

 

Myrddyn Phillips (May 2022)

 

Mapping Mountains - Summit Relocations - Y Trichant

Foel Fawr (SH 679 057) - 25th summit relocation

Significant Height Revisions post for Foel Fawr

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their location, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Foel Fawr (SH 679 057)

The criteria for the list that this summit relocation applies to are: 

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Foel Fawr, and it is adjoined to the Tarren y Gesail group of hills, which are situated in the south-western part of North Wales (Region A, Sub-Region A3), and it is positioned with the B4405 road to its north-west and a minor road to its north-east, and has the town of Machynlleth towards the south-east. 

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was listed with a 348m summit height, based on the spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and which is positioned at SH 67959 05849. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.  

LIDAR summit image of Foel Fawr (SH 679 057)

The summit height produced by LIDAR analysis is 343.9m and is positioned at SH 67982 05743, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies to when the high point is positioned in a different field, to a different feature such as a conifer plantation, within a different map contour, a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist. 

Therefore, the summit height produced by LIDAR analysis is 343.9m and this is positioned at SH 67982 05743, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 110 metres southward from where the previously listed summit is positioned. 

 

The full details for the hill are:

Group:  Tarren y Gesail 

Name:  Foel Fawr 

OS 1:50,000 map:  124

Summit Height:  343.9m (LIDAR)                                                           

Summit Grid Reference (New Position):  SH 67982 05743 (LIDAR) 

Bwlch Height:  286.5m (LIDAR) 

Bwlch Grid Reference:  SH 67651 05532 (LIDAR) 

Drop:  57.4m (LIDAR) 

 

Myrddyn Phillips (March 2022)

Mapping Mountains - Summit Relocations - Y Trichant

Mynydd Du (SH 805 084) - 24th summit relocation

Hill Reclassifications post for Mynydd Du

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their location, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Mynydd Du (SH 805 084)

The criteria for the list that this summit relocation applies to are: 

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Mynydd Du, and it is adjoined to the Aran Fawddwy group of hills, which are situated in the south-western part of North Wales (Region A, Sub-Region A3), and it is positioned with minor roads to its north and south, the A487 road to its west and the A470 road to its east, and has the village of Aberllefenni towards the west north-west. 

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category. 

Extract from the Ordnance Survey 1:25,000 Explorer map

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with 19m of drop, based on the 335m summit spot height positioned at SH 80470 08382 that appears on the Ordnance Survey 1:50,000 Landranger map and the 316m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

Extract from the Ordnance Survey 1:50,000 Landranger map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.  

LIDAR summit image of Mynydd Du (SH 805 084)

The summit that LIDAR identifies is 335.8m in height and positioned at SH 80572 08424, with the caveat that there is only partial LIDAR coverage for the summit area of this hill, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies to when the high point is positioned in a different field, to a different feature such as a conifer plantation, within a different map contour, a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist. 

Therefore, the listed summit height of this hill is 335.8m and its new position is SH 80572 08424, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 100 metres north-eastward from where the previously listed summit is positioned. 

 

The full details for the hill are:

Group:  Aran Fawddwy 

Name:  Mynydd Du 

OS 1:50,000 map:  124, 125

Summit Height:  335.8m (LIDAR)                                                           

Summit Grid Reference (New Position):  SH 80572 08424 (LIDAR) 

Bwlch Height:  314.9m (LIDAR) 

Bwlch Grid Reference:  SH 80738 08624 (LIDAR) 

Drop:  20.9m (LIDAR) 

 

Myrddyn Phillips (February 2022)

Mapping Mountains - Summit Relocations - Y Trichant

Y Llan Wern Fawr (SN 893 300) - 23rd summit relocation

Significant Name Changes post for Y Llan Wern Fawr

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their location, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Y Llan Wern Fawr (SN 893 300)

The criteria for the list that this summit relocation applies to are: 

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Y Llan Wern Fawr and this was derived from the Tithe map, and it is adjoined to the Mynydd Epynt group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its north-west and east, and the A40 road to its south, and has the village of Pontsenni (Sennybridge) towards the east south-east. 

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was listed with an estimated c 350m summit height based on the small uppermost ring contour that appears on the contemporary Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Y Llan Wern Fawr (SN 893 300)

The height produced by LIDAR analysis for the remaining natural summit of this hill is 350.0m and is positioned at SN 89305 30085, with LIDAR analysis also giving a raised field boundary positioned at SN 89295 30077 a height of 350.1m, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies to when the high point is positioned in a different field, to a different feature such as a conifer plantation, within a different map contour, a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist. 

Therefore, the summit height produced by LIDAR analysis is 350.0m and this is positioned at SN 89305 30085, this position is to the remaining natural summit of the hill and is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 10 metres from where LIDAR indicates the slightly higher raised field boundary to be positioned. 

 

The full details for the hill are:

Group:  Mynydd Epynt 

Name:  Y Llan Wern Fawr 

OS 1:50,000 map:  160

Summit Height:  350.0m (LIDAR)                                                           

Summit Grid Reference (New Position):  SN 89305 30085 (LIDAR) 

Bwlch Height:  318.0m (LIDAR) 

Bwlch Grid Reference:  SN 89043 30577 (LIDAR) 

Drop:  32.1m (LIDAR) 

 

Myrddyn Phillips (February 2022)

 

 

Mapping Mountains - Summit Relocations - Y Trichant

Pt. 353.6m (SJ 249 539) - 22nd summit relocation

Survey post for Pt. 353.6m

Hill Reclassifications post for Pt. 353.6m

Significant Name Changes post for Pt. 353.6m

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their location, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data and from LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Pt. 353.6m (SJ 249 539)

The criteria for the list that this summit relocation applies to are: 

Y Trichant- The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The hill is being listed by the point (Pt. 353.6m) notation as an appropriate name for it either through local enquiry and / or historic research has not been found by the author, and it is adjoined to the Moel y Gamelin group of hills, which are situated in the north-eastern part of North Wales (Region A, Sub-Region A2), and it is positioned with minor roads to its north, east and south, the B5430 road to its west and the A525 road farther to its south, and has the village of Bwlchgwyn towards the east south-east. 

Extract from the Ordnance Survey 1:25,000 Explorer map

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was listed under the transposed and invented name of Gwern Hill with a 353m summit height, based on the spot height that appeared on the Ordnance Survey 1:50,000 Landranger map of the day and which was positioned at SJ 251 543.  This 353m height is based on an old imperial Surface Height of 1158.3ft (353.1m) that appears on the Ordnance Survey series of Six-Inch maps. 

Extract from the Ordnance Survey series of Six-Inch maps

The summit of this hill was subsequently listed as a twin top with the prioritised summit position relocated when the Ordnance Survey Vector Map local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available maps and for this hill a 353m spot height appeared positioned at SJ 250 539. 

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR image of Pt. 353.6m (SJ 249 539)

LIDAR analysis confirms the top positioned at SJ 249 539 as being higher than 353.1m and as this summit has now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies to when the high point is positioned in a different field, to a different feature such as a conifer plantation, within a different map contour, a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist. 

The Trimble GeoXH 6000 gathering data at the summit of Pt. 353.6m

Therefore, the summit height produced by the Trimble GeoXH 6000 survey is 353.6m and this is positioned at SJ 24997 53989, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 380 metres southward from where the previously listed summit is positioned. 

 

The full details for the hill are:

Group:  Moel y Gamelin 

Name:  Pt. 353.6m 

OS 1:50,000 map:  117

Summit Height:  353.6m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference (New Position):  SJ 24997 53989 (Trimble GeoXH 6000) 

Bwlch Height:  c 322m (interpolation) 

Bwlch Grid Reference:  SJ 24041 53999 (interpolation) 

Drop:  c 32m (Trimble GeoXH 6000 summit and interpolated bwlch) 

 

Myrddyn Phillips (November 2021)

Mapping Mountains - Summit Relocations - Y Trichant

Pen Aran Hill (SO 137 888) - 21st summit relocation

Survey post for Pen Aran Hill

Significant Name Changes post for Pen Aran Hill

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Pen Aran Hill (SO 137 888)

The criteria for the list that this summit relocation applies to are: 

Y Trichant- The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Pen Aran Hill and this was derived from local enquiry, and it is adjoined to the Cilfaesty group of hills, which are situated in Mid and West Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its north-west and south-east and the A489 road to its north-east, and has the village of Ceri (Kerry) towards the north-east.

Extract from the Ordnance Survey 1:50,000 Landranger map

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was listed under the name of Penarron with a 368m summit height, based on the spot height that appears on the Ordnance Survey 1:50,000 Landranger map and which is positioned at SO 13837 89083. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Pen Aran Hill

The summit area of this hill consists of three tops with LIDAR analysis giving two of these tops within 1mm of each other: 

 

367.818m at SO 13829 89079 

367.819m at SO 13711 88853 

 

These two tops and an intermediary third top were surveyed with the Trimble GeoXH 6000, resulting in the following heights and positions: 

 

367.942m at SO 13828 89079 

367.252m at SO 13754 88924 

368.031m at SO 13710 88852 

 

As the summit has now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies to when the high point is positioned in a different field, to a different feature such as a conifer plantation, within a different map contour, a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist. 

The Trimble GeoXH 6000 gathering data at the old summit position of Pen Aran Hill

The Trimble GeoXH 6000 gathering data at the new summit position of Pen Aran Hill
 

Therefore, the summit height produced by the Trimble GeoXH 6000 survey is 368.0m and this is positioned at SO 13710 88852, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 240 metres south-westward from where the previously listed summit is positioned. 

 

The full details for the hill are:

Group:  Cilfaesty

Name:  Pen Aran Hill 

OS 1:50,000 map:  136

Summit Height:  368.0m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference (New Position):  SO 13710 88852 (Trimble GeoXH 6000) 

Bwlch Height:  324.6m (LIDAR) 

Bwlch Grid Reference:  SO 13561 88411 (LIDAR) 

Drop:  43.4m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (October 2021)

 

Mapping Mountains - Summit Relocations - Y Trichant

Pen y Bryn Mawr (SN 705 732) - 20th summit relocation

Survey post for Pen y Bryn Mawr

 

There has been confirmation of a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales and Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height and their locations, the drop, dominance and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

The forested summit of Pen y Bryn Mawr (SN 705 732)

The criteria for the two listings that this summit relocation applies to are: 

Y Trichant- The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

Y Trechol – The Dominant Hills of Wales – Welsh P30 hills whose prominence equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015, and the list is now available in its entirety on Mapping Mountains in Google Doc format. 

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Pen y Bryn Mawr and it is adjoined to the Elenydd group of hills which are situated in the western part of Mid and West Wales (Region B, Sub-Region B2), and it is encircled by minor roads with the A4120 road farther to its north, the B4340 road farther to its west and the B4343 road farther to its east, and has the village of Pont-rhyd-y-groes towards the east. 

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was listed under the name of Cefn Blewog with a 341m summit height based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map and which is positioned at SN 70556 72711. 

Extract from the Ordnance Survey 1:25,000 Explorer map

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 115m of drop and 33.72% dominance, based on the 341m summit spot height and an estimated c 226m bwlch height, based on interpolation of 10m contouring between 220m – 230m that appears on the Ordnance Survey 1:25,000 Explorer map. 

The details of this hill were later re-examined and its summit position relocated to Pen y Bryn Mawr, this hill is due north of Cefn Blewog and although it does not possess a summit spot height on contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps, its uppermost 340m ring contour is larger than that given Cefn Blewog and therefore Pen y Bryn Mawr was listed with an estimated c 342m summit height, and when coupled with an emended c 224m bwlch height, these values gave Pen y Bryn Mawr an estimated c 118m of drop and 34.50% dominance. 

LIDAR image of Pen y Bryn Mawr (SN 705 732) and Cefn Blewog (SN 705 727)

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

The summit height produced by LIDAR analysis for these two hills is given below:

 

341.619m at SN 70567 73222 for Pen y Bryn Mawr

 

340.660m at SN 70552 72709 for Cefn Blewog

 

This comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies when the hill’s high point is found to be positioned; in a different field, within a different map contour, to a different feature such as in a conifer plantation, to a different point where a number of potential summit positions are within close proximity, a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist, or when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct. 

The Trimble GeoXH 6000 at the summit of Pen y Bryn Mawr

Therefore, the listed summit height of this hill is 341.6m and its new position is SN 70567 73222, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 500 metres northward from where the previously listed summit is positioned. 

 

The full details for the hill are:

Group:  Elenydd

Name:  Pen y Bryn Mawr 

OS 1:50,000 map:  135, 147

Summit Height:  341.6m (LIDAR)                                                           

Summit Grid Reference (New Position):  SN 70567 73222 (LIDAR) 

Bwlch Height:  222.8m (LIDAR) 

Bwlch Grid Reference:  SN 72170 73551 (LIDAR) 

Drop:  118.8m (LIDAR) 

Dominance:  34.77% (LIDAR) 

 

Myrddyn Phillips (September 2021)

 

Mapping Mountains - Summit Relocations - Y Trichant

Mynydd Tŷ’r Sais (SH 855 004) - 19th summit relocation

Survey post for Mynydd Tŷ’r Sais

Hill Reclassifications post for Mynydd Tŷ’r Sais

Significant Height Revisions post for Mynydd Tŷ’r Sais

  

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by a Trimble GeoXH 6000 survey, prompted by an enquiry from Ronnie Bowron based on detail in the summit analysis programme produced by Joe Nuttall. 

Mynydd Tŷ'r Sais (SH 855 004)

The criteria for the list this summit relocation affects are:

Y Trichant- The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Mynydd Tŷ’r Sais and it is adjoined to the Pumlumon group of hills, which are situated in the north-western part of Mid and West Wales (Region B, Sub-Region B2), and it is positioned with the A470 road to its north, minor roads to its west and south, and the B4518 road to its east, and has the village of Llanbrynmair towards the north-east. 

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category. 

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with 26m of drop, based on the 359m summit spot height positioned at SH 85453 00439 that appears on the Ordnance Survey 1:50,000 Landranger and the 1:25,000 Explorer map and the 333m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

Since the original publication of the P30 lists of Geoff Crowder’s v-g.me website there have been a number of Ordnance Survey maps made available online, some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website, whilst others are current and digitally updated such as the mapping on the OS Maps website and the WalkLakes website. 

One of the resources now available online is the mapping on the OS Maps website.  This is the replacement for OS Get-a-map and until recent times had contours at 5m intervals which were proving consistently more accurate compared to the 5m contours that sometimes appear on the Ordnance Survey 1:25,000 Explorer map and used to appear on the online Vector Map Local.  This mapping shows an uppermost 360m ring contour and bwlch contouring much nearer the 330m height when compared to the contouring on the Ordnance Survey 1:25,000 Explorer map. 

Another resource now available online is the mapping on the WalkLakes website which hosts an interactive map originated from the Ordnance Survey Open Data programme.  This map has many spot heights not on other publicly available Ordnance Survey maps and for this hill a 362m spot height is given on the area of its summit and again the bwlch contouring is much nearer the 330m height when compared to the contouring on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the WalkLakes website

These details resulted in this hill being prioritised for a Trimble GeoXH 6000 survey.  This took place on the 30.03.21 resulting in a 362.2m summit height positioned at SH 85514 00483, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies when the hill’s high point is found to be positioned; in a different field, to a different feature such as in a conifer plantation, placed within a different map contour, to a different point where a number of potential summit positions are within close proximity, or when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist. 

The Trimble GeoXH 6000 gathering data at the summit of Mynydd Tŷ'r Sais

Therefore, the listed summit height of this hill is 362.2m and its new position is SH 85514 00483, this position is not given a spot height on contemporary Ordnance Survey maps, but does have a 362m spot height on the interactive mapping hosted on the WalkLakes website and is approximately 60 metres north-eastward from where the previously listed summit is positioned. 

 

The full details for the hill are:

Group:  Pumlumon

Name:  Mynydd Tŷ’r Sais 

OS 1:50,000 map:  135, 136

Summit Height:  362.2m (converted to OSGM15)                                                           

Summit Grid Reference (New Position):  SH 85514 00483 

Bwlch Height:  329.9m (converted to OSGM15) 

Bwlch Grid Reference:  SH 86220 00690 

Drop:  32.2m 

 

Myrddyn Phillips (July 2021)

  

Mapping Mountains - Summit Relocations - Y Trichant

Top Field (SJ 070 055) - 18th summit relocation

Survey post for Top Field

Hill Reclassifications post for Top Field

Significant Name Changes post for Top Field

 

There has been confirmation of a summit position whose details can be included as a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Top Field (SJ 070 055)

The criteria for the list this summit relocation affects are:

Y Trichant- The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Top Field and this was derived from local enquiry, and it is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is encircled by minor roads, with the A458 road further to its north and the B4389 road further to its east, and has the small town of Llanfair Caereinion towards the east north-east. 

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the P30 lists were standardised, and interpolated heights and drop values also included, this hill was listed with an estimated c 32m of drop based on the 335m summit spot height positioned at SJ 07085 05586 and an estimated c 303m bwlch height based on interpolation of 10m contouring that appear on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR image of Top Field (SJ 070 055)

When on the hill the position of the summit given by LIDAR was surveyed using the Trimble GeoXH 6000 as well as another position that looked of similar height.  The second position was to an elevated mound above a small quarry and upon investigation it was decided that this was man-made.

 

The result for each position is given below: 

Natural summit:  333.257m at SJ 07082 05572 

Man-made elevated mound:  333.339m at SJ 07203 05559

 

The result produced by LIDAR analysis gives this hill a summit height of 333.1m, and as the natural summit has now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies when the hill’s high point is found to be positioned; in a different field, to a different feature such as in a conifer plantation, placed within a different map contour, to a different point where a number of potential summit positions are within close proximity, or when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist. 

Gathering data with the Trimble GeoXH 6000 at the natural summit of Top Field

Gathering data with the Trimble GeoXH 6000 at the man-made mound

Therefore, the listed summit height of this hill is 333.3m and its confirmed position is SJ 07082 05572, this position is given a spot height on contemporary Ordnance Survey maps and is approximately 80 metres westward from where a slightly higher man-made mound is positioned. 

 

The full details for the hill are:

Group:  Carnedd Wen 

Name:  Top Field 

OS 1:50,000 map:  125

Summit Height:  333.3m (converted to OSGM15, Trimble GeoXH 6000)                                                      

Summit Grid Reference (Confirmed Position):  SJ 07082 05572 (Trimble GeoXH 6000) 

Bwlch Height:  301.1m (LIDAR) 

Bwlch Grid Reference:  SJ 06237 05273 (LIDAR) 

Drop:  32.2m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (March 2021)

Mapping Mountains - Summit Relocations - Y Trichant

Y Dduallt (ST 041 961) - 17th summit relocation

Hill Reclassifications post for Y Dduallt

Significant Height Revisions post for Y Dduallt

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived by Joe Nuttall who produced a summit analysis programme using LIDAR, and then by LIDAR analysis initially conducted by Jim Bloomer and subsequently by Myrddyn Phillips. 

LIDAR image of Y Dduallt (ST 041 961)

The criteria for the list this summit relocation affects are:

Y Trichant- The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Y Dduallt, and it is adjoined to the Cymoedd Morgannwg group of hills, which are situated in the central part of South Wales (Region C, Sub-Region C2), and it is encircled by minor roads with the A4233 road further to its west and the A4059 road and the A470 road further to its east, and has the town of Pontypridd towards the south-east. 

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for this sub category. 

After the P30 lists were standardised, and interpolated heights and drop values also included, this hill was listed with 21m of drop based on the 354m summit spot height positioned at ST 04088 96112 and the 333m bwlch spot height that appear on the Ordnance Survey 1:25,000 Explorer map.  With its adjacent hill positioned at ST 036 958 listed with an estimated c 360m summit height based on the uppermost ring contour that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

Both summits have now been analysed via LIDAR.  The summit height produced by LIDAR analysis for this hill is 363.0m positioned at ST 04179 96153, as this is higher than the 361.4m adjacent summit positioned at ST 03647 95811, their respective bylchau are swapped.  The revised summit position for this hill comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies when the hill’s high point is found to be positioned; in a different field, to a different feature such as in a conifer plantation, placed within a different map contour, to a different point where a number of potential summit positions are within close proximity, or when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist. 

Therefore, the listed summit height of this hill is 363.0m and its new position is ST 04179 96153, this position is not given a spot height on contemporary Ordnance Survey maps and is approximately 100 metres north-eastward from where the previously listed summit is positioned. 

 

The full details for the hill are:

Group:  Cymoedd Morgannwg 

Name:  Y Dduallt 

OS 1:50,000 map:  170

Summit Height:  363.0m (LIDAR)                                                           

Summit Grid Reference (New Position):  ST 04179 96153 (LIDAR) 

Bwlch Height:  312.2m (LIDAR) 

Bwlch Grid Reference:  ST 03283 95733 (LIDAR) 

Drop:  50.8m (LIDAR)

 

Myrddyn Phillips (January 2021)

Mapping Mountains - Summit Relocations - Y Trichant

Blaen Pathiog (SN 927 820) - 16th summit relocation

Hill Reclassifications post for Blaen Pathiog

Significant Height Revisions post for Blaen Pathiog

 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

LIDAR image of Blaen Pathiog (SN 927 820)

The criteria for the list this summit relocation affects are:

Y Trichant- The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Blaen Pathiog and it is adjoined to the Pumlumon group of hills, which are situated in the north-western part of Mid and West Wales (Region B, Sub-Region B2), and it is positioned with the A470 road to its south-east, and has the town of Llanidloes towards the north-east. 

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category, and listed with a 377m summit height, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

After the P30 lists were standardised, and interpolated heights and drop values also included, this hill was listed with an estimated c 33m of drop based on the 379m summit spot height positioned at SN 92619 82039 that appeared on the Ordnance Survey Vector Map Local that was hosted on the Geograph website and an estimated c 346m bwlch height, based on interpolation of 10m contouring between 340m – 350m.  The 379m summit spot height has latterly also appeared on the online mapping available on the Magic Maps website. 

Extract from the Magic Maps website

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Blaen Pathiog

The summit height produced by LIDAR analysis is 376.1m and this is positioned at SN 92776 82003, and as the summit has now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the hill’s high point is found to be positioned; in a different field, to a different feature such as in a conifer plantation, placed within a different map contour, to a different point where a number of potential summit positions are within close proximity, or when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist. 

The Trimble GeoXH 6000 gathering data at the summit of Blaen Pathiog

Therefore, the listed summit height of this hill is 376.3m and its new position is SN 92775 82001, this position is given a 377m spot height on contemporary Ordnance Survey 1:25,000 Explorer maps and is approximately 160 metres east south-eastward from where the previously listed summit is positioned.

 

The full details for the hill are:

Group:  Pumlumon

Name:  Blaen Pathiog

OS 1:50,000 map:  136

Summit Height:  376.3m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference (New Position):  SN 92775 82001 (Trimble GeoXH 6000)

Bwlch Height: 343.3m (LIDAR)

Bwlch Grid Reference:  SN 92760 81765 (LIDAR)

Drop:  33.1m (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

Myrddyn Phillips (January 2021)

 

Mapping Mountains - Summit Relocations - Y Trichant

Mynydd Derw Llwydion (SN 904 900) - 15th summit relocation

1st survey post for Mynydd Derw Llwydion

2nd survey post for Mynydd Derw Llwydion

Hill Reclassifications post for Mynydd Derw Llwydion

Significant Height Revisions post for Mynydd Derw Llwydion

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by a Trimble GeoXH 6000 survey and LIDAR analysis conducted by Myrddyn Phillips.

Mynydd Derw Llwydion (SN 904 900)

The criteria for the list this summit relocation affects are:

Y Trichant- The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13th May 2017.

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Mynydd Derw Llwydion and it is adjoined to the Pumlumon group of hills, which are situated in the north-western part of Mid and West Wales (Region B, Sub-Region B2), and it is positioned with minor roads to its north and west, and the B4518 road to its south, and has the town of Llanidloes towards the south-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the accompanying Hills to be surveyed sub list, and listed with a 387m summit height, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map and which is positioned at SN 90722 90066.

Extract from the Ordnance Survey 1:25,000 Explorer map

The summit and bwlch of this hill were surveyed using the Trimble GeoXH 6000 on the 18^th April 2014, resulting in a 388.1m summit height taken to the position of the 387m spot height and a 358.1m bwlch height, with the hill being reclassified to Trichant status due to this survey.

Gathering data during the first summit survey of this hill

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR analysis gave the position of the summit to the west of where the 387m spot height appears on the map, which is also where the first Trimble GeoXH 6000 survey was conducted, therefore the summit position given by LIDAR was visited on the 11^th July 2020 and a data set taken with the Trimble GeoXH 6000 from its high point.

LIDAR image of Mynydd Derw Llwydion

The summit height produced by the second Trimble GeoXH 6000 survey is 389.3m and this is positioned at SN 90460 90041, and this revised summit position comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the hill’s high point is found to be positioned; in a different field, to a different feature such as in a conifer plantation, placed within a different map contour, to a different point where a number of potential summit positions are within close proximity, or when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist. 

Gathering data during the second summit survey of this hill

Therefore, the listed summit height of this hill is 389.3m and its new position is SN 90460 90041, this position is not given a spot height on contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps and is approximately 300 metres westward from where the previously listed summit is positioned.

The full details for the hill are:

Group:  Pumlumon

Name:  Mynydd Derw Llwydion

OS 1:50,000 map:  136

Summit Height:  389.3m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference (New Position):  SN 90460 90041 (Trimble GeoXH 6000)

Bwlch Height: 358.1m (converted to OSGM15, Trimble GeoXH 6000)

Bwlch Grid Reference:  SN 90391 90264 (Trimble GeoXH 6000)

Drop:  31.3m (Trimble GeoXH 6000)

For details on the first Trimble GeoXH 6000 survey of this hill

For details on the second Trimble GeoXH 6000 survey of this hill

Myrddyn Phillips (November 2020)

Mapping Mountains - Summit Relocations - Y Trichant

Cefn Twrch (SN 899 317) - 14th summit relocation

Hill Reclassifications post for Cefn Twrch

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR.

LIDAR image of Cefn Twrch (SN 899 317)

This was initiated by Joe Nuttall who produced a summit analysis programme that used LIDAR with an alternative height map (DEM) allowing identification of summits and cols and thereby drops.  The resulting spreadsheet that Joe produced contains over 29,600 hills.

This spreadsheet is being evaluated by DoBIH Editors and others, and for this particular hill it was Chris Crocker who initially assessed its height and that of its adjacent peak via LIDAR analysis.

Myrddyn Phillips then evaluated this hill’s details via LIDAR analysis and confirmed its height and drop and hence the confirmation of its summit relocation.

The criteria for the list this summit relocation affects are:

Y Trichant- The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13th May 2017.

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Cefn Twrch, and it is adjoined to the Mynydd Epynt group of hills, which are situated in the south-eastern part of Mid and West Wales (Region B, Sub-Region B2), and it is positioned with minor roads to its east, north and west and the A40 road to its south, and has the hamlet of Pentre-bach towards the north-east.

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for the accompanying main P30 list, and it was listed as a 378m map heighted twin summit with the prioritised summit positioned at SN 898 321 and its twin map heighted summit positioned at SN 904 307.   

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 32m of drop based on the twin 378m summit spot heights that appear on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 346m bwlch height based on interpolation of 10m contouring between 340m – 350m.

Extract from the Ordnance Survey 1:25,000 Explorer map

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not shown on other publicly available Ordnance Survey maps and for this hill it showed a 342m bwlch spot height and when coupled with the 378m summit spot height it gave this hill 36m of drop. 

However, it was not until LIDAR became available that the details for these two summits could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

The LIDAR result for each summit appears below:

Cefn Twrch (previous prioritised twin summit)    379.4m at SN 89923 31751

Cefn Twrch (previous non-prioritised twin summit)    377.8m at SN 90489 30697

The prioritised summit is confirmed the higher, although its position has moved from where the 378m spot height appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps, and its drop confirmed sufficient for it to be classified as a Trichant, with the drop of the old twin summit confirmed as 11.6m which is insufficient for it to be classified as a Sub-Trichant.

The summit height produced by LIDAR analysis is 379.4m positioned at SN 89923 31751 and this revised summit position comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the hill’s high point is in a different field, or where a number of potential summit positions are within close proximity and the highest point is not where previously given, or when it is positioned to a different feature such as in a conifer plantation, or when the high point of the hill is placed within a different map contour, or when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

LIDAR summit image for Cefn Twrch

Therefore, the listed summit height of this hill is 379.4m and its new position is SN 89923 31751, this position is not given a spot height on contemporary Ordnance Survey maps and is approximately 440 metres southward from where the previously listed summit is positioned.

The full details for the hill are:

Group:  Mynydd Epynt

Name:  Cefn Twrch

OS 1:50,000 map:  160

Summit Height:  379.4m (LIDAR)

Summit Grid Reference (New Position):  SN 89923 31751 (LIDAR)

Bwlch Height:  347.2m (LIDAR)

Bwlch Grid Reference:  SN 89591 32567 (LIDAR)

Drop:  32.2m (LIDAR)

Myrddyn Phillips (September 2020)

Mapping Mountains - Summit Relocations - Y Trichant

Banc y Gorlan (SH 922 037) and Cerrig y Tân (SH 917 039) - 13th summit relocation

There has been a Twin Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales and the Y Pedwarau – The 400m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail on historic and contemporary maps produced from Ordnance Survey data.

This was initiated by Joe Nuttall who produced a summit analysis programme that used LIDAR with an alternative height map (DEM) allowing identification of summits and bylchau and thereby drops.  The resulting spreadsheet that Joe produced contains over 29,600 hills.

This spreadsheet is being evaluated by a number of people, including Ronnie Bowron, who passed the details of this hill to us.

The criteria for the lists this summit relocation affects are:

Y Trichant- The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13th May 2017.

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

Y Pedwarau – The 400m Hills of Wales.  Welsh hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main Y Pedwarau list are five categories of sub hills, with this hill listed in the 390m Double Sub-Pedwar category.  The criteria for 390m Double Sub-Pedwar status being all Welsh hills at or above 390m and below 400m in height that have 20m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is published on Mapping Mountains in Google Doc format.

Y Pedwarau - The 400m Hills of Wales by Myrddyn Phillips and Aled Williams

The prioritised name the hill is listed by is Banc y Gorlan with the new twin summit listed as Cerrig y Tân, and it is adjoined to the Carnedd Wen group of hills which are situated in the southern part of North Wales (Region A, Sub-Region A4), and it is positioned with minor roads to its west and east, and the A470 road to its south, and has the village of Llanbrynmair towards the south-west.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, and listed as Banc y Gorlan with a 396m summit height based on the spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 1^st edition of the Y Pedwarau was published by Europeaklist in May 2013 and the 390m sub categories included, this hill was listed with the same details as above; with a c 29m estimated drop value also given to the hill.  However, it was noted that to the north-west of this summit another 390m contour was shown on contemporary Ordnance Survey maps, this had no spot height and the summit was named Cerrig y Tân.

   

Extract from the Ordnance Survey series of Six-Inch maps

The details for this hill have been re- assessed due to Joe Nuttall’s summit analysis and Ronnie Bowron’s evaluation, with examination of the Ordnance Survey series of Six-Inch maps and mapping available on the WalkLakes website, resulting in the summit of Cerrig y Tân being listed with the same height as Banc y Gorlan.  Although not an individual summit relocation it is still worth documenting under this heading.

Extract from the WalkLakes website

The above detail comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the hill’s high point is in a different field, or where a number of potential summit positions are within close proximity and the highest point is not where previously given, or when it is positioned to a different feature such as in a conifer plantation, or when the high point of the hill is placed within a different map contour, or when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the listed summit height of this hill remains at 396m and for now the prioritised summit remains Banc y Gorlan positioned at SH 92237 03720, with the new twin summit of Cerrig y Tân positioned at SH 91785 03936.  The summit of Cerrig y Tân is not given a spot height on contemporary Ordnance Survey maps but has a 396m spot height on the WalkLakes map and a 1300ft height on the Ordnance Survey series of Six-Inch maps.

The full details for the hill are:

Group:  Carnedd Wen

Name:  Banc y Gorlan

OS 1:50,000 map:  136

Summit Height:  396m (spot height)

Summit Grid Reference:  SH 92237 03720 (spot height)

Name:  Cerrig y Tân

OS 1:50,000 map:  136

Summit Height:  396m (spot height)

Summit Grid Reference (New Twin Summit):  SH 91785 03936 (spot height)

Bwlch Height:  c 368m (interpolation)

Bwlch Grid Reference:  SH 91788 04224 (interpolation)

Drop:  c 28m (spot height summit and interpolated bwlch)

Myrddyn Phillips and Aled Williams (September 2020)






Mapping Mountains - Summit Relocations - Y Trichant

Cefn Uchaf (SJ 012 461) - 12th summit relocation

Hill Reclassifications post for Cefn Uchaf

Significant Name Changes post for Cefn Uchaf

Significant Height Revisions post for Cefn Uchaf

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Cefn Uchaf (SJ 012 461)

The criteria for the list this summit relocation affects are:

Y Trichant- The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13th May 2017.

The name the hill is listed by is Cefn Uchaf and this was derived from the Tithe map, and it is adjoined to the Mynydd Hiraethog group of hills which are situated in the north-eastern part of North Wales (Region A, Sub-Region A2), and it is positioned with the B5105 road to its north, the A5 road to its south and the A494 road to its east, and has the town of Corwen towards the east south-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was not included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for this sub category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with 2om of drop, based on the 337m summit spot height that appears at SJ 01390 46054 on the Ordnance Survey 1:25,000 Explorer map and the 317m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map.

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR summit image of Cefn Uchaf

The summit height produced by LIDAR analysis is 340.0m positioned at SJ 01294 46112 and this revised summit position comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the hill’s high point is in a different field, or where a number of potential summit positions are within close proximity and the highest point is not where previously given, or when it is positioned to a different feature such as in a conifer plantation, or when the high point of the hill is placed within a different map contour, or when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the listed summit height of this hill is 340.0m and its new position is SJ 01294 46112, this position is not given a spot height on contemporary Ordnance Survey maps and is approximately 100 metres north-westward from where the previously listed summit is positioned.

The full details for the hill are:

Group:  Mynydd Hiraethog

Name:  Cefn Uchaf

OS 1:50,000 map:  116

Summit Height:  340.0m (LIDAR)

Summit Grid Reference (New Position):  SJ 01294 46112 (LIDAR)

Bwlch Height:  319.1m (LIDAR)

Bwlch Grid Reference:  SJ 00949 46115 (LIDAR)

Drop:  20.9m (LIDAR)

Myrddyn Phillips (August 2020)

Mapping Mountains - Summit Relocations - Y Trichant

Wenlli (SH 845 655) - 11th summit relocation

Significant Name Changes post for Wenlli

Hill Reclassifications post for Wenlli

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed from detail on contemporary Ordnance Survey maps and hand-held GPS submissions to DoBIH.

LIDAR image of Wenlli (SH 845 655)

The criteria for the list this summit relocation affects are:

Y Trichant- The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13th May 2017.

The name the hill is now listed by is Wenlli and this was derived from the Tithe map, and it is adjoined to the Rhos group of hills which are situated in the northern part of North Wales (Region A, Sub-Region A2), and it is positioned with the B5113 road to its west and the A548 road to its south and east, and has the town of Llanrwst towards the south-west.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 list. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 30m of drop, based on the twin 308m map heighted summits with the prioritised summit position given to the spot height that appears at SH 846 654 on Ordnance Survey 1:25,000 Explorer maps, and an estimated c 278m bwlch height.

Extract from the Ordnance Survey 1:25,000 Explorer map

The details for this hill were re-examined when the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps.  However, as this mapping had no additional spot heights of note the details for this hill remained the same.

The details for this hill were also re-assessed when the OS Maps website became available online.  This is the replacement for OS Get-a-map and has contours at 5m intervals which are proving consistently more accurate compared to the 5m contours that sometimes appear on Ordnance Survey 1:25,000 Explorer maps and used to appear on the online Vector Map Local.  This re-assessment resulted in the hill being listed with an estimated c 277m bwlch height based on interpolation of 5m contouring between 275m – 280m and therefore increasing its drop value to c 31m.

During these re-assessments the position of this hill’s summit was relocated to match a hand-held GPS position submitted to DoBIH, and although an accurate survey would be needed to confirm this position, for now it is being taken for that of the summit.

The revised summit position comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to any listed hill whose summit meets the following criteria; where there are a number of potential summit positions within close proximity and the highest point is not where previously given, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist, or when the summit of the hill is in a different field compared to where previously given, or when it is positioned to a different feature such as in a conifer plantation, or when the high point of the hill is placed within a different map contour compared to its previous listed position, or when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct.

Therefore, the listed summit height of this hill is 308m and this is positioned at SH 84520 65553, and this is in a different field to the previously listed summit position and approximately 100 metres north-westward from it.

The full details for the hill are:

Group:  Rhos

Name:  Wenlli

OS 1:50,000 map:  116

Summit Height:  308m (spot height)

Summit Grid Reference (New Position):  SH 84520 65553 (hand-held GPS via DoBIH)

Bwlch Height:  c 277m (interpolation)

Bwlch Grid Reference:  SH 83917 65689 (interpolation)

Drop:  c 31m (hand-held GPS via DoBIH and interpolated bwlch)

Myrddyn Phillips (March 2020)

Mapping Mountains - Summit Relocations - Y Trichant

Yr Allt (SO 196 358) - 10th summit relocation

Hill Reclassifications post for Yr Allt

Significant Name Changes post for Yr Allt

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Yr Allt (SO 196 358)

The criteria for the list this summit relocation affects are:

Y Trichant- The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13th May 2017.

The name the hill is listed by is Yr Allt and it is adjoined to the Mynyddoedd Duon group of hills which are situated in the eastern part of South Wales (Region C, Sub-Region C3), and it is positioned with minor roads to its west, north and east, with the A4078 road further to its west and the A438 road further to its north-west, and has the village of Aberllynfi (Three Cocks) towards the north-west.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 list. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 31m of drop, based on an estimated c 335m summit height and an estimated c 304m bwlch height.

Extract from the Ordnance Survey 1:25,000 Explorer map

The details for this hill were re-examined when the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map became available online.  This mapping has many spot heights not on any other publicly available Ordnance Survey map and gives a 302m spot height on the area of this hill’s bwlch.  This spot height is also shown on Ordnance Survey data that appears on the Magic Maps website.

During the re-assessment of this hill’s details the summit height was amended to 334m based on the 1096ft (334.06m) imperial height positioned at SO 19663 35913 that appears on the summit area of this hill on the series of Ordnance Survey Six-Inch maps.  These re-assessments resulted in the hill being listed with 32m of drop.

Extract from the series of Ordnance Survey Six-Inch maps

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR summit image for Yr Allt

The summit height produced by LIDAR analysis is 334.0m positioned at SO 19677 35879, with LIDAR also giving a 334.1m height positioned at SO 19663 25913 to a raised field boundary that is excluded from the height of this hill as it is considered a recent man-made construct and with the natural summit of the hill positioned in a different field compared to where the summit was originally listed.  The above detail comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to any listed hill whose summit meets the following criteria; where there are a number of potential summit positions within close proximity and the highest point is not where previously given, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist, or when the summit of the hill is in a different field compared to where previously given, or when it is positioned to a different feature such as in a conifer plantation, or when the high point of the hill is placed within a different map contour compared to its previous listed position, or when the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct.

Close up LIDAR summit image for Yr Allt

Therefore, the summit height produced by LIDAR analysis is 334.0m to ground meeting the criteria used within this list and this is positioned at SO 19677 35879, this is in a different field to the previously listed summit position which matches the LIDAR position of the highest part of the raised field boundary and is approximately 35 metres southward from it, and as the raised field boundary is considered a relatively recent man-made construct it is not taken as a part of the height of this hill.

The full details for the hill are:

Group:  Mynyddoedd Duon

Name:  Yr Allt

OS 1:50,000 map:  161

Summit Height:  334.0m (LIDAR, natural summit)

Summit Grid Reference (New Position):  SO 19677 35879 (LIDAR, natural summit)

Bwlch Height:  301.7m (LIDAR)

Bwlch Grid Reference:  SO 20120 35549 (LIDAR)

Drop:  32.3m (LIDAR)

Myrddyn Phillips (January 2020)






Mapping Mountains - Summit Relocations - Y Trichant

Fforest (SN 944 900) - 9th summit relocation

There has been a Summit Relocation to a hill that is listed in the Y Pedwarau – The 400m Hills of Wales and the Y Trichant – The 300m Hills of Wales, with the summit height and its position confirmed via LIDAR analysis conducted by Aled Williams.

LIDAR image of Fforest (SN 944 900)

The criteria for the two listings this summit relocation affects are:

Y Pedwarau – The 400m Hills of Wales.  Welsh hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main Y Pedwarau list are five categories of sub hills, with this summit relocation applying to a hill listed in the 390m Sub-Pedwar category, with the criteria for this sub category being all Welsh hills at or above 390m and below 400m in height that have a minimum 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams, with the Introduction to the Mapping Mountains publication of this list appearing on the 30th January 2017, and the list is now available in its entirety on Mapping Mountains in Google Doc format.

Y Trichant – The 300m Hills of Wales.  Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13th May 2017.

The name the hill is listed by is Fforest and it is adjoined to the Pumlumon group of hills, which are situated in the northern part of Mid and West Wales (Region B, Sub-Region B2), and it is encircled by minor roads and has the Afon Trannon to its north and a part of the B4569 road towards the east, and has the village of Trefeglwys towards the east north-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website the summit height of this hill was listed as 391m which was based on the spot height positioned at SN 94301 90124 that appears on the Ordnance Survey 1:25,000 Explorer map.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 1^st edition of the Y Pedwarau was published by Europeaklist in May 2013 the hill appeared under the details given above using the six figure grid reference of SN 943 901.  These details were amended for the Y Pedwarau list appearing on Mapping Mountains with the ten figure summit grid reference of SN 94294 90127 used, with this being taken from details on DoBIH.

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR bwlch image for Fforest

The summit height produced by LIDAR analysis is 391.5m at SN 94401 90011 and its position in relation to that previously given comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to any listed hill whose summit meets the following criteria; where there are a number of potential summit positions within close proximity and the highest point is not where previously given, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist, or when the summit of the hill is in a different field compared to where previously given, or when it is positioned to a different feature such as in a conifer plantation, or when the high point of the hill is placed within a different map contour compared to its previous listed position, or when the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct.

Therefore, the summit height produced by LIDAR analysis is 391.5m and is positioned at SN 94401 90011, this position is not given a spot height on contemporary Ordnance Survey maps and is approximately 120 metres south-eastward from where the previously listed summit is positioned.

The full details for the hill are:

Group:  Pumlumon

Name:  Fforest 

OS 1:50,000 map:  136

Summit Height:  391.5m (LIDAR)

Summit Grid Reference (New Position):  SN 94401 90011 (LIDAR)

Bwlch Height: 355.8m (LIDAR)

Bwlch Grid Reference:  SN 93945 89099 (LIDAR)

         

Drop:  35.7m (LIDAR)

Myrddyn Phillips and Aled Williams (November 2019)

Mapping Mountains - Summit Relocations - Y Trichant

Y Foel (SJ 026 407) - 8th summit relocation

There has been a Summit Relocation to a hill that is listed in the Y Pedwarau and the Y Trichant, with the summit height and its position confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR summit image of Y Foel (SJ 026 407)

The criteria for the two listings this summit relocation affects are:

Y Pedwarau - Welsh hills at or above 400m and below 500m in height that have 30m minimum drop.  Accompanying the main Y Pedwarau list are five categories of sub hills, with this summit relocation applying to a hill listed in the 390m Sub-Pedwar category, with the criteria for this sub category being all Welsh hills at or above 390m and below 400m in height that have a minimum 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams, with the Introduction to the Mapping Mountains publication of this list appearing on the 30^th January 2017.

Y Trichant – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017.

The name of the hill is Y Foel and it is adjoined to the Arenig group of hills, which are situated in the central part of North Wales (Region A, Sub-Region A3), and it is positioned with the A494 road to the north-west and the Afon Dyfrdwy (River Dee) and the B4401 road to the south-east, and has the small community of Cynwyd towards the east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website the summit height of this hill was listed as 392m which was based on the spot height adjoined to a triangulation pillar positioned at SJ 02550 40750 on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.  The latter map also records a 391m spot height adjoined to a small ancient enclosure positioned to the east south-east of the triangulation pillar.

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

Unfortunately LIDAR only covers the land adjoined to the ancient enclosure and not that adjoined to the triangulation pillar, however the flush bracket adjoined to the trig pillar is recorded as 391.972m, therefore ground at its base will be approximately 391.6m – 391.7m in height.   

The summit height produced by LIDAR analysis for land adjoined to the ancient enclosure is 392.85m at SJ 02666 40700 and its position in relation to that previously given comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to any listed hill whose summit meets the following criteria; where there are a number of potential summit positions within close proximity and the highest point is not where previously given, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist, or when the summit of the hill is in a different field compared to where previously given, or when the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct.

Therefore, the summit height produced by LIDAR analysis is 392.85m and is positioned at SJ 02666 40700, this position is given a 391m spot height on the Ordnance Survey 1: 25,000 Explorer map and is approximately 130 metres east south-eastward from where the previously listed summit is positioned which is land at the base of the triangulation pillar which is given a 392m spot height on contemporary Ordnance Survey maps.

The full details for the hill are:

Group:  Arenig

Name:  Y Foel

OS 1:50,000 map:  125

Summit Height:  392.85m (LIDAR)

Summit Grid Reference (New Position):  SJ 02666 40700 (LIDAR)

Bwlch Height: 327m (spot height)

Bwlch Grid Reference:  SJ 01843 40765 (spot height)

         

Drop:  66m (LIDAR summit and spot height bwlch)

Myrddyn Phillips and Aled Williams (November 2019)

Mapping Mountains - Summit Relocations - Y Trichant

Mynydd y Grug (ST 177 906) - 7th summit relocation

Significant Height Revisions post for Mynydd y Grug

There has been a Summit Relocation to a hill that is listed in the Y Trichant, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Mynydd y Grug (ST 177 906)

The criteria for the listing that this summit relocation applies to are:

Y Trichant – Welsh hills at or above 300m and below 400m in height with 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017.

The name of the hill is Mynydd y Grug and it is adjoined to the Cymoedd Gwent group of hills, which are situated in the eastern part of South Wales (Region C, Sub-Region C2), and it is positioned with the A469 road to its west, the B4251 and the Afon Sirhywi (Sirhowy River) to its north-east and the A468 road to its south, and has the town of Caerffili (Caerphilly) towards the south-west.

When the original Welsh 300m P30 list was published on Geoff Crowder’s v-g.me website this hill was listed with a 348m summit height, based on the spot height positioned at ST 17688 90958 that appears on the Ordnance Survey 1:25,000 Explorer map, with an accompanying note stating; Workings probably obliterated 350c top at ST176908 on 1986 1:50000 map.  As heights on 1:25,000 scale mapping were prioritised in this list over those on 1:50,000 scale mapping this hill’s summit was listed to where the 348m spot height appears on the 1:25,000 Explorer map.

Extract from the old Ordnance Survey 1:25,000 Explorer map

Extract from the contemporary Ordnance Survey 1:50,000 Landranger map

The details for this hill were re-assessed when the Ordnance Survey Vector Map became available online and this shows a 375m summit spot height with contemporary Ordnance Survey 1:25,000 Explorer maps showing an uppermost 370m ring contour and a raised summit area which is the bi-product of mine waste spoil.

Extract from the contemporary Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Mynydd y Grug

The summit height produced by LIDAR analysis and its position in relation to that previously given comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to any listed hill whose summit meets the following criteria; where there are a number of potential summit positions within close proximity and the highest point is not where previously given, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist, or when the summit of the hill is in a different field compared to where previously given, or when the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct.  As heights on different scaled Ordnance Survey maps are not consistent the height given on the 1:25,000 Explorer map is being prioritised in favour of the 1:50,000 Landranger map for detailing these relocations.

The summit height produced by LIDAR analysis is 374.2m and is positioned at ST 17753 90669, this position is given a 375m spot height on the contemporary Ordnance Survey Vector map and is approximately 275 metres south south-eastward from the previously listed summit position where the 348m spot height appears on the Ordnance Survey 1:25,000 Explorer map.  

The full details for the hill are:

Group:  Cymoedd Gwent

Name:  Mynydd y Grug

OS 1:50,000 map:  171

Summit Height:  374.2m (LIDAR)

Summit Grid Reference (new position):  ST 17753 90669 (LIDAR)

Bwlch Height:  169.85m (LIDAR)

Bwlch Grid Reference:  ST 16783 95144 (LIDAR)

Drop:  204.3m (LIDAR)

Myrddyn Phillips (July 2019)

Mapping Mountains - Summit Relocations - Y Trichant

Mynydd y Lan (ST 209 923) - 6th summit relocation

Significant Height Revisions post for Mynydd y Lan

There has been a Summit Relocation to a hill that is listed in the Y Trichant and Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Mynydd y Lan (ST 209 923)

The criteria for the two listings that this summit relocation applies to are:

Y Trichant – Welsh hills at or above 300m and below 400m in height with 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017.

Y Trechol – The Dominant Hills of Wales – Welsh P30 hills whose prominence equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015.

The name of the hill is Mynydd y Lan and it is adjoined to the Cymoedd Gwent group of hills, which are situated in the eastern part of South Wales (Region C, Sub-Region C2), and it is encircled by roads with the B4251 to its south and west, the A472 to its north and the A467 and B4591 and the Afon Ebwy (Ebbw River) to its east, and has the town of Trecelyn (Newbridge) towards the north and the village of Pontycymer (Crosskeys) towards the east.

When the original Welsh 300m P30 list was published on Geoff Crowder’s v-g.me website this hill was listed with a 381m summit height, based on the spot height positioned at ST 20794 92508 that appears on the Ordnance Survey 1:25,000 Explorer map, with an accompanying note stating that the Ordnance Survey 1:50,000 Landranger map has a 385m spot height positioned at ST 20898 92357.  As heights on 1:25,000 scale mapping were prioritised in this list over those on 1:50,000 scale mapping this hill’s summit was listed to where the 381m spot height appears on the 1:25,000 Explorer map.

Extract from the Ordnance Survey 1:25,000 Explorer map

Extract from the Ordnance Survey 1:50,000 Landranger map

Since publication of these P30 lists on Geoff Crowder’s v-g.me website there have been a number of Ordnance Survey maps made available online, some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website, whilst others are current and digitally updated such as the Vector Map Local hosted on the Geograph website, and which is entitled the Interactive Coverage Map, and in the case of this hill it is the series of Ordnance Survey Six-Inch maps where the origins of the 385m spot height that appears on the 1:50,000 Landranger map can be traced, as the Six-Inch map surveyed in 1875 and published in 1885 has a 1263.6ft (385.15m) surface height at the same position as the contemporary 385m spot height.

Extract from the Ordnance Survey series of Six-Inch maps

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR summit image of Mynydd y Lan

The summit height produced by LIDAR analysis and its position in relation to that previously given comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to any listed hill whose summit meets the following criteria; where there are a number of potential summit positions within close proximity and the highest point is not where previously given, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist, or when the summit of the hill is in a different field compared to where previously given, or when the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct.  As heights on different scaled Ordnance Survey maps are not consistent the height given on the 1:25,000 Explorer map is being prioritised in favour of the 1:50,000 Landranger map for detailing these relocations.

The summit height produced by LIDAR analysis is 381.3m and is positioned at ST 20903 92337, this position is given a 385m spot height on contemporary Ordnance Survey 1:50,000 Landranger maps and is approximately 200 metres south south-eastward from the previously listed summit position where the 381m spot height appears on the Ordnance Survey 1:25,000 Explorer map.  

The full details for the hill are:

Group:  Cymoedd Gwent

Name:  Mynydd y Lan

OS 1:50,000 map:  171

Summit Height:  381.3m (LIDAR)

Summit Grid Reference (new position):  ST 20903 92337 (LIDAR)

Bwlch Height:  159.5m (LIDAR)

Bwlch Grid Reference:  ST 19806 96725 (LIDAR)

Drop:  221.8m (LIDAR)

Dominance:  58.17% (LIDAR)

Myrddyn Phillips (July 2019)






Mapping Mountains - Summit Relocations - Y Trichant

Foel Gron (SH 583 621) - 5th summit relocation

Survey post for Foel Gron

There has been a Summit Relocation to a hill that is listed in the Y Trichant, and which was initiated by LIDAR analysis and confirmed by a survey with the Trimble GeoXH 6000, both of which were conducted by Myrddyn Phillips, with the latter taking place on the 06 & 10.10.18.

Foel Gron (SH 583 621)

The criteria for the list that this summit relocation applies to are:

Y Trichant – Welsh hills at or above 300m and below 400m in height with 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017.

The name of the hill is Foel Gron and it is adjoined to the Glyderau group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is encircled by minor roads with the A4244 road to the north-west and the A4086 road and Llyn Padarn to the south-west, and has the villages of Deiniolen towards the north and Llanberis towards the south.

LIDAR image of Foel Gron

When the original Welsh 300m P30 list was published on Geoff Crowder’s v-g.me website this hill was listed with a 353m summit height, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map which is positioned at SH 58390 62231 on the eastern side of a stone wall that crosses the upper part of this hill.

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website with the cursor indicating the position of the relocated summit

Three positions on the summit area of this hill were surveyed with the Trimble GeoXH 6000, resulting in:

1^st position: 351.577 at SH 58388 62224

2^nd position:  351.482m at SH 58403 62175

3^rd position:  351.585m at SH 58359 62170

The Trimble GeoXH 6000 gave the third position as the higher, and this corresponds with LIDAR analysis.

LIDAR summit image of Foel Gron

The summit height produced by the Trimble GeoXH 6000 is 351.6m and is positioned at SH 58359 62170 and its position in relation to that previously given comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to any listed hill whose summit meets the following criteria; where there are a number of potential summit positions within close proximity and the highest point is not where previously given, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist, or when the summit of the hill is in a different field compared to where previously given, or when the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct.  As heights on different scaled Ordnance Survey maps are not consistent the height given on the 1:25,000 Explorer map is being prioritised in favour of the 1:50,000 Landranger map for detailing these relocations.

The summit height produced by the Trimble GeoXH 6000 survey is 351.6m and is positioned at SH 58359 62170, this position is not given a spot height on contemporary Ordnance Survey maps and is approximately 65 metres south south-westward from where the 353m spot height appears on the Ordnance Survey 1:25,000 Explorer map.  

Gathering data with the Trimble GeoXH 6000 at the summit of Foel Gron (on right) with the old position of the summit on the left

The full details for the hill are:

Group:  Glyderau

Name:  Foel Gron

OS 1:50,000 map:  114, 115

Summit Height:  351.6m (converted OSGM15)

Summit Grid Reference (new position):  SH 58359 62170

Bwlch Height:  319.3m (LIDAR)

Bwlch Grid Reference:  SH 58675 62194 (LIDAR)

  

Drop:  32.3m (Trimble summit and LIDAR bwlch)

For details on the survey that relocated the summit position of this hill

Myrddyn Phillips (March 2019)

Mapping Mountains - Summit Relocations - Y Trichant

Cefn Llanbister (SO 116 733) - 4th summit relocation

Survey post for Cefn Llanbister

Significant Height Revisions post for Cefn Llanbister

There has been a Summit Relocation to a hill that is listed in the Y Trichant, and which was initiated by LIDAR analysis and confirmed by a survey with the Trimble GeoXH 6000, both of which were conducted by Myrddyn Phillips, with the latter taking place on the 03.07.18 in warm and clear conditions.

Cefn Llanbister (SO 116 733)

The criteria for the list that this summit relocation applies to are:

Y Trichant – Welsh hills at or above 300m and below 400m in height with 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and its renaming appearing on Mapping Mountains on the 13^th May 2017.

The name of the hill is Cefn Llanbister and it is placed in the Beacon Hill group of hills, which are situated in the north-eastern part of Mid and West Wales (Region B, Sub-Region B1), and it is positioned with the Afon Ieithon (River Ithon) and the A 483 road to its west and the B 4356 road to its north, and has the small community of Llanbister at its base to the west of the summit.

As the summit of the hill is a part of open access land it can be approached from most directions with public footpaths accessing this land from the west and east, with the most convenient access to the hill via a track that leaves the B 4356 road just to the north of the summit.

When the original Welsh 300m P30 list was published on Geoff Crowder’s v-g.me website this hill was listed with a 373m summit height based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map, with an accompanying note stating 376m at SO GR117732 on 1986 1:50000 map.

Extract from the Ordnance Survey 1:25,000 Explorer map

Prior to LIDAR analysis and the subsequent survey with the Trimble GeoXH 6000 the listed height of this hill had been revised to 376m based on the spot height on the Ordnance Survey 1:50,000 Landranger map.

Extract from the Ordnance Survey 1:50,000 Landranger map

The summit height produced by the Trimble GeoXH 6000 survey is 377.5m (converted to OSGM15) at SO 11690 73303 and its position in relation to that previously given comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to any listed hill whose summit meets the following criteria; where there are a number of potential summit positions within close proximity and the highest point is not where previously given, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist, or when the summit of the hill is in a different field compared to where previously given, or when the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct.  As heights on different scaled Ordnance Survey maps are not consistent the height given on the 1:25,000 Explorer map is being prioritised in favour of the 1:50,000 Landranger map for detailing these relocations.

The summit height produced by the Trimble GeoXH 6000 survey is 377.5m (converted to OSGM15) and is positioned at SO 11690 73303, this position is not given a spot height on contemporary Ordnance Survey maps and is approximately 100 metres east from where the 376m spot height appears on the Ordnance Survey 1:50,000 Landranger map and 450 metres north-west from where the 373m spot height appears on the Ordnance Survey 1:25,000 Explorer map.   

The Trimble GeoXH 6000 gathering data at the summit of Cefn Llanbister which confirmed the summit relocation of this hill

The full details for the hill are:

Group:  Beacon Hill

Name:  Cefn Llanbister

OS 1:50,000 map:  136, 148

Summit Height:  377.5m (converted OSGM15)

Summit Grid Reference (new position):  SO 11690 73303

Bwlch Height:  335.3m (converted to OSGM15)

Bwlch Grid Reference:  SO 12399 74601 

Drop:  42.2m (converted to OSGM15)

For details on the survey that relocated the summit position of this hill

Myrddyn Phillips (November 2018)

Mapping Mountains - Summit Relocations - Y Trichant

Ffridd Top Llety (SJ 089 167) - 3rd summit relocation

Survey post for Ffridd Top Llety

Significant Name Changes post for Ffridd Top Llety

There has been a Summit Relocation to a hill that is listed in the Y Trichant and which was initiated by LIDAR analysis, with the summit height, its position and the drop of the hill confirmed by a survey with the Trimble GeoXH 6000, which was conducted on the 5^th April 2018.

LIDAR image of Bryn (on left) and Ffridd Top Llety (on right)

The criteria for the list that this summit relocation affects are:

Y Trichant – All Welsh hills at and above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub category entitled the Sub-Trichant consisting of all Welsh hills at and above 300m and below 400m in height that have 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips and the Introduction to the list and the re-naming and publication history was published on Mapping Mountains on the 13^th May 2017. 

The name of the enclosed land where the summit of this hill is situated is Ffridd Top Llety and this was derived from local enquiry, and the hill is adjoined to the Y Berwyn range of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and is positioned between the B 4393 road to its north and the B 4382 road to its west, and has the small community of Llanfihangel-yng-Ngwynfa towards the west.

Ffridd Top Llety (SAJ 089 167)

As the summit of the hill is not on designated open access land permission to visit should be sought, for those wishing to do so there are two public footpaths that cross the field where the summit is situated and which come within a few metres of its high point.

When this hill was originally listed in the Welsh P30 lists on Geoff Crowder’s v-g.me website it was by the name of Bryn and its 347m map heighted summit location given as SJ 085 169.  Since this hill was first listed the Ordnance Survey Interactive Coverage Map hosted on the Geograph website has become available online and this map shows a second 347m map heighted summit positioned at SJ 089 167. 

Gathering data at the summit of Ffridd Top Llety

These two summits and their respective connecting bylchau were analysed via LIDAR and surveyed with the Trimble GeoXH 6000.  The resulting summit data is given below:

Bryn

LIDAR:  346.239m at SJ 08501 16871

Trimble GeoXH 6000:  346.367m at SJ 08501 16870

Ffridd Top Llety

LIDAR:  346.619m at SJ 08997 16749

Trimble GeoXH 6000:  346.551m at SJ 08997 16748 

Therefore, the confirmation of the position of the relocated summit is at SJ 08997 16748 and this consists of closely cropped grass in an enclosed grazing field, this position is approximately 500 metres east south-eastward from where the previous prioritised 347m map heighted summit of Bryn is located.

The Trimble GeoXH 6000 gathering data at the summit of Bryn with the position of the relocated summit of Ffridd Top Llety in the background on the left

The full details for the hill are:

Group:  Y Berwyn

Summit Height:  346.6m (converted to OSGM15)

Name:  Ffridd Top Llety

OS 1:50,000 map:  125

Summit Grid Reference (New Position):  SJ 08997 16748  

       

Drop:  69.6m (converted to OSGM15)

For details on the survey that confirmed the summit relocation of this hill

Myrddyn Phillips (May 2018)

Mapping Mountains - Summit Relocations - Y Trichant

Upper Park (SJ 189 052) - 2nd summit relocation

Survey post for Upper Park

Significant Height Revisions post for Upper Park

There has been confirmation of a Summit Relocation to a hill that is listed in the Y Trichant and Y Trechol – The Dominant Hills of Wales, and which was initiated by a survey with the Trimble GeoXH 6000, with the survey that confirmed this summit relocation taking place on the 7^th January 2018.

The criteria for the two listings that this summit relocation affects are:

Y Trichant - Welsh hills at and above 300m and below 400m in height that have 30m minimum drop. 

Y Trechol - The Dominant Hills of Wales - These are the Welsh P30 hills whose prominence  equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those addition Welsh P30 hills whose prominence is 33% or more and below 50% of their absolute height.

The name of the hill is Upper Park and it is situated in the Carnedd Wen range of hills which are in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is positioned between the A 458 road to its north and the A 483 road to its south-east, and has the town of Y Trallwng (Welshpool) to its north-east.

Upper Park (SJ 189 052)

As the summit of the hill is not on designated open access land and a part of a private estate permission to visit should be sought, for those wishing to do so there are a number of options for an ascent, all of which use tracks through forested plantations.

When this hill was originally listed in the Welsh P30 lists on Geoff Crowder’s v-g.me website the summit position was given as SJ 189 052, and although this six figure grid reference matches that of the position of the confirmed relocation, its position was to the 352m spot height that appears on the Ordnance Survey 1:25,000 Explorer map (SJ 18895 05292).

Two data sets were taken with the Trimble GeoXH 6000, the first at the high point of the hill which is in a deciduous plantation known as Crown Wood.  The second was taken to the high point of the adjacent field where the 352m spot height appears, these results are given below:

1^st survey, inside Crown Wood at high point of hill:  354.0m (converted to OSGM15)

2^nd survey, adjacent field where the 352m spot height appears:  352.4m (converted to OSGM15)

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website showing the summit position in relation to the spot height position

Therefore, the confirmation of the position of the relocated summit is at SJ 18980 05270 and this is ground within a deciduous wood, this position is approximately 100 metres east south-eastward from where the 352m spot height appears on the Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Group:  Carnedd Wen

Summit Height:  354.0m (converted to OSGM15)

Name:  Upper Park

OS 1:50,000 map:  125

Summit Grid Reference (New Position):  SJ 18980 05270 

        

Drop:  177.0m (converted to OSGM15)

Dominance:  49.998%

The Trimble GeoXH 6000 gathering data at the summit of Upper Park with the position of where the 352m spot height appears on the ground in the frosted field in the centre background of this photo

For details on the survey that confirmed the summit relocation of this hill

Myrddyn Phillips (February 2018)

Mapping Mountains - Summit Relocations - Y Trichant

The two tops of Cefn Bach have now been surveyed with the Trimble GeoXH 6000, resulting in:

Surveyed on 18.08.15: 389.392m at SO 00293 37291

Surveyed on 30.12.18:  389.391m at SO 00470 38742

With 1mm difference in height the Trimble is unable to split these summits, therefore they are reinstated as twin Trichant tops, the post below remains as originally written for historic merit.

 


Cefn Bach (SO 002 372) - 1st summit relocation

1st Survey post for Cefn Bach

2nd Survey post for Cefn Bach


There has been a de-twinning of summits that is being detailed as a Summit Relocation initiated by a survey with the Trimble GeoXH 6000 in conjunction with LIDAR data analysed by Aled Williams, with this hill listed in both the Y Pedwarau and the Y Trichant, with the following details being retrospective as the Trimble survey that partly resulted in this summit relocation was conducted on 18^th August 2015.

The Y Pedwarau comprise the 400m hills of Wales that have a minimum 30m of drop, accompanying the main P30 list are also a number of sub lists.  Whilst the Y Trichant comprise the 300m hills of Wales that have a minimum 30m of drop with an accompanying sub list entitled the Sub-Trichant.

The hill has twin map heighted 391m summits which are orientated north to south, both are a part of the hill named as Cefn Bach and therefore each summit is listed by this name.  Prior to the survey with the Trimble and the analysis of LIDAR data the southerly summit at SO 002 372 was prioritised and listed as a 390m Sub-Pedwar and a Trichant with 55m of drop, whilst the northerly summit at SO 003 387 was listed as a 390m Double Sub-Pedwar and Sub-Trichant with c 22m of drop.   

The survey with the Trimble GeoXH 6000 was conducted in the southern hills of Mynydd Epynt on a fine and bright day during a circuit of three hills, with the hill positioned between the small communities of Merthyr Cynog to the west and Lower Chapel to the east south-east. 

The two summits are easily accessed from a narrow lane to their south where one car can be squeezed onto the grass verge.  This ascent requires a there and back walk, alternatively a similar there and back walk can be taken from a lane to the north-west of the northerly summit.

Unfortunately there was only sufficient time to survey the southerly of these two summits with the Trimble GeoXH 6000, and therefore an accurate value for the northerly summit awaited analysis of LIDAR data.

Aled’s analysis of LIDAR data for the northerly summit of Cefn Bach gives the following details:

Cefn Bach

Summit Height:  389.2m

Summit Grid Reference:  SO 00471 38745

Bwlch Height:  368.9m

Bwlch Grid Reference:  SO 00075 38322

Drop:  20.3m

The Trimble survey and Aled's analysis of LIDAR data for the southerly summit of Cefn Bach gives the following details:

Cefn Bach

Summit Height:  389.4m

Summit Grid Reference:  SO 00293 37291

Bwlch Height:  335.0m

Bwlch Grid Reference:  SO 00293 36953

Drop:  54.4m

Therefore, as both hills are under 390m in height their status within the Y Pedwarau is deleted.  Whilst their status within the Y Trichant is now confirmed and remains as it was. 

The full details for the northerly hill are:

The full details for the hill are:

Cardinal Hill:  Clepyn Melyn

Summit Height:  389.2m (LIDAR data)

Name:  Cefn Bach

OS 1:50,000 map:  160

Summit Grid Reference:  SO 00471 38745

Drop:  20.3m (LIDAR data)

The full details for the southerly hill are:

Cardinal Hill:  Clepyn Melyn

Summit Height:  389.4m (converted to OSGM15) (Trimble and LIDAR data)

Name:  Cefn Bach

OS 1:50,000 map:  160

Summit Grid Reference:  SO 00293 37291

Drop:  54.4m (Trimble and LIDAR data)

The Trimble GeoXH 6000 gathering data at the southerly summit (SO 002 372) which in conjunction with LIDAR data de-twinned the two 391m map heighted summits of Cefn Bach

For details on the survey that in conjunction with LIDAR data de-twinned and confirmed the summit position of this hill please click {here}

Myrddyn Phillips (August 2015)