Mapping Mountains – Summit Relocations – 200m Twmpau

200m Twmpau – Summit Relocations

The 200m Twmpau (thirty welsh metre prominences and upward) are the Welsh hills at or above 200m and below 300m in height that have a minimum drop of 30m.  Accompanying the main P30 list is a sub list entitled the 200m Sub-Twmpau with the qualification to this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop.

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 - 200m Twmpau

Bwlchwernen Fach (SN 606 556) - 35th summit relocation

Hill Reclassifications post for Bwlchwernen Fach

Significant Name Changes post for Bwlchwernen Fach

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 Bwlchwernen Fach (SN 606 556)

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

200m Twmpau - Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Bwlchwernen Fach and this was derived from the Tithe map, and it is adjoined to the Mynydd Bach group of hills, which are situated in the western part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its north and west, and the A485 road to its south-east, and has the village of Llanddewibrefi towards the east.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was not included in the accompanying 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 24m of drop, based on the 256m summit spot height positioned at SN 60698 55674 that appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 232m bwlch height, based on interpolation of 10m contouring between 230m – 240m. 

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 257.4m positioned at SN 60696 55677.  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 Bwlchwernen Fach (SN 606 556)

The height produced by LIDAR analysis to the highest remaining natural ground of this hill is 256.35m positioned at SN 60699 55684, 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 256.35m and this is positioned at SN 60699 55684, this position is close to where the 256m spot height appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 7 metres north-eastward from the high point of the raised field boundary. 

 

The full details for the hill are: 

Group:  Mynydd Bach 

Name:  Bwlchwernen Fach 

OS 1:50,000 map:  146

Summit Height:  256.35m (LIDAR) 

Summit Grid Reference (New Position):  SN 60699 55684 (LIDAR) 

Bwlch Height:  230.7m (LIDAR) 

Bwlch Grid Reference:  SN 60598 55268 (LIDAR) 

Drop:  25.7m (LIDAR) 

 

Myrddyn Phillips (January 2024)

Mapping Mountains - Summit Relocations - 200m Twmpau

Graig (SN 537 108) - 34th summit relocation

Significant Name Changes post for Graig

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 (SN 537 108)

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

200m Twmpau - Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Graig and this was derived from the Tithe map, and it is adjoined to the Mynydd Sylen group of hills, which are situated in the southern part of South Wales (Region B, Sub-Region B5), and it is positioned with a minor road to its west, the B4306 road to its south and the B4310 and A476 roads to its north-west, and has the village of Y Tymbl towards the north.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was listed as a twin summit with a height of c 220m and its prioritised summit positioned at SN 538 109. 

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

Since the original publication of the Welsh P30 lists on Geoff Crowder’s v-g.me website there have been a number of 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 were digitally updated such as the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map, whilst others are current and digitally updated such as the interactive mapping on the Magic Maps and WalkLakes websites.

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated against the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.  This mapping had many spot heights not on other publicly available maps and for this hill it had a 223m summit spot height positioned at SN 53874 11032.

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 Graig (SN 537 108) with the previously listed summit position to the north-east

LIDAR analysis gives the highest ground on this hill as 223.35m positioned at SN 53762 10849.  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 Graig (SN 537 108) in relation to the raised field boundary

The height produced by LIDAR analysis to the natural summit of this hill is 223.1m positioned at SN 53789 10889, and this position in relation to the previously listed summit position and 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 223.1m and this is positioned at SN 53789 10889, 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 145 metres south-westward from the previously listed summit position which was based on the 223m spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map, and 40 metres north-eastward from the high point of the raised field boundary. 

 

The full details for the hill are: 

Group:  Mynydd Sylen 

Name:  Graig 

OS 1:50,000 map:  159

Summit Height:  223.1m (LIDAR) 

Summit Grid Reference (New Position):  SN 53789 10889 (LIDAR) 

Bwlch Height:  199.2m (LIDAR) 

Bwlch Grid Reference:  SN 54478 10875 (LIDAR) 

Drop:  23.9m (LIDAR) 

 

Myrddyn Phillips (January 2024)

Mapping Mountains - Summit Relocations - 200m Twmpau

Parc Uchaf Gwydyr (SH 792 597) - 33rd summit relocation

Significant Height Revisions post for Parc Uchaf Gwydyr

  

There has been confirmation of a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 Parc Uchaf Gwydyr (SH 792 597)

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

200m Twmpau - Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Parc Uchaf Gwydyr, and it is adjoined to the Carnedd Llywelyn group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with a minor road to its north-west, the A5 road to its south-west, and the B5106 road to its east, and has the town of Betws-y-coed towards the south.

When the original 200m 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 272m, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map and which is positioned at SH 79181 60064. 

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

When the accompanying sub list to the 200m height band of Welsh P30 hills published on Geoff Crowder’s v-g.me website was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and its summit relocated to SH 79186 59729 and listed with an estimated height of c 274m.

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 Parc Uchaf Gwydyr (SH 792 597)

LIDAR analysis gives the highest ground on this hill as 276.7m positioned at SH 79204 59775, as opposed to its originally listed summit position which LIDAR analysis gives as 270.3m positioned at SH 79182 60067, and this new position 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 276.7m and this is positioned at SH 79204 59775, 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 290 metres southward and in a different map contour from where the 272m spot height and its originally listed summit is positioned. 

 

The full details for the hill are: 

Group:  Carnedd Llywelyn 

Name:  Parc Uchaf Gwydyr 

OS 1:50,000 map:  115

Summit Height:  276.7m (LIDAR) 

Summit Grid Reference (New Position):  SH 79204 59775 (LIDAR) 

Bwlch Height:  225.2m (LIDAR) 

Bwlch Grid Reference:  SH 78923 59652 (LIDAR) 

Drop:  51.5m (LIDAR) 

 

Myrddyn Phillips (November 2023)

Mapping Mountains - Summit Relocations - 200m Twmpau

Blaen Pibydd (SN 286 337 and SN 286 336) - 32nd summit relocation

Hill Reclasifications post for Blaen Pibydd

Significant Name Changes post for Blaen Pibydd

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail produced by JoeNuttall in his surface analysis programme, with subsequent LIDAR analysis conducted by the DoBIH team and independently by Myrddyn Phillips. 

LIDAR image of Blaen Pibydd (SN 286 337 and SN 286 336)

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

200m Twmpau - Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Blaen Pibydd and this was derived from the Tithe map, 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 encircled by minor roads, with the B4299 road farther to its south-east, and has the town of Castellnewydd Emlyn (Newcastle Emlyn) towards the north north-east.

When the original 200m 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 224m, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map which is positioned at SN 28673 33662. 

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 224.4m positioned at SN 28648 33672.  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 Blaen Pibydd (SN 286 337 and SN 286 336)

The height produced by LIDAR analysis to the natural summit of this hill is 223.9m positioned at SN 28692 33707 and SN 28695 33701 and SN 28696 33697 and SN 28694 33695, 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 223.9m and this is to the natural summit of the hill which is positioned at SN 28692 33707 and SN 28695 33701 and SN 28696 33697 and SN 28694 33695, although relatively close to where the 224m spot height is positioned, none of these positions are given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and they are approximately 45 metres north-eastward from where the high point of the raised field boundary is positioned. 

 

The full details for the hill are: 

Group:  Mynydd Pencarreg 

Name:  Blaen Pibydd 

OS 1:50,000 map:  145

Summit Height:  223.9m (LIDAR) 

Summit Grid Reference (New Position):  SN 28692 33707 & SN 28695 33701 & SN 28696 33697 & SN 28694 33695 (LIDAR) 

Bwlch Height:  195.0m (LIDAR) 

Bwlch Grid Reference:  SN 28588 33103 (LIDAR) 

Drop:  28.8m (LIDAR) 

 

Myrddyn Phillips (September 2023)

Mapping Mountains - Summit Relocations - 200m Twmpau

Parc Lan Uchaf (SN 100 261) - 31st summit relocation

Significant Name Changes post for Parc Lan Uchaf

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau 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 Parc Lan Uchaf (SN 100 261)

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

200m Twmpau - Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau 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 now listed by is Parc Lan Uchaf and this was derived from the Tithe map, and it is adjoined to the Mynydd Preseli 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 B4313 road to its west and minor roads to its south and east, and has the village of Maenclochog towards the north-west.When the original 200m 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 c 200m based on the uppermost contour that appears on the Ordnance Survey 1:25,000 Explorer map which is positioned at SN 100 260. 

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 Parc Lan Uchaf (SN 100 261)

LIDAR analysis gives the highest ground on this hill as 201.3m positioned at SN 10035 26167.  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.

The height produced by LIDAR analysis to the natural summit of this hill is 201.2m positioned at SN 10053 26179, 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 201.2m and this is to the natural summit of the hill which is positioned at SN 10053 26179, 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 20 metres north-eastward from where the high point of the raised field boundary is positioned. 

 

The full details for the hill are: 

Group:  Mynydd Preseli 

Name:  Parc Lan Uchaf 

OS 1:50,000 map:  145, 158

Summit Height:  201.2m (LIDAR) 

Summit Grid Reference (New Position):  SN 10053 26179 (LIDAR) 

Bwlch Height:  129.0m (LIDAR) 

Bwlch Grid Reference:  SN 09509 26745 (LIDAR) 

Drop:  72.2m (LIDAR) 

Dominance:  35.90% (LIDAR) 

 

Myrddyn Phillips (March 2023)

Mapping Mountains - Summit Relocations - 200m Twmpau

Crugiau Maen Saeson (SN 141 456) - 30th summit relocation

Significant Name Changes post for Crugiau Maen Saeson

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau 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 Crugiau Maen Saeson (SN 141 456)

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

200m Twmpau - Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau 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 Myrddn Phillips

The name the hill is now listed by is Crugiau Maen Saeson and this was derived from local enquiry, and it is adjoined to the Mynydd Preseli group of hills, which are situated in the south-western part of South Wales (Region B, Sub-Region B1), and it is positioned encircled by minor roads, with the B4546 road farther to its north-east and the A487 road farther to its south-east, and has the town of Aberteifi (Cardigan) towards the east.

When the original Welsh 200m P30 list was published on Geoff Crowder’s v-g.me website, this hill was listed with a summit height of 205m, which is adjoined to a triangulation pillar with a flush bracket height of 205.224m positioned at SN 14170 45534 and which 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. 

LIDAR summit image of Crugiau Maen Saeson (SN 141 456)

The summit height produced by LIDAR analysis is 205.3m positioned at SN 14104 45618 and SN 14106 45618 which corresponds with the position of an ancient tumulus, 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 205.3m and this is positioned at SN 14104 45618 and SN 14106 45618, 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 positioned to a different feature approximately 90 metres north-westward from where the originally listed summit is positioned. 

 

The full details for the hill are: 

Group:  Mynydd Preseli 

Name:  Crugiau Maen Saeson 

OS 1:50,000 map:  145

Summit Height:  205.3m (LIDAR) 

Summit Grid Reference (New Position):  SN 14104 45618 & SN 14106 45618 (LIDAR) 

Bwlch Height:  c 127m (interpolation) 

Bwlch Grid Reference:  SN 15174 41089 (interpolation) 

Drop:  c 78m (LIDAR summit and interpolated bwlch) 

Dominance:  38.13% (LIDAR summit and interpolated bwlch) 

 

Myrddyn Phillips (March 2023)

  

Mapping Mountains - Summit Relocations - 200m Twmpau

Cae Gwar Tŷ (SN 656 640) - 29th summit relocation

Significant Name Changes post for Cae Gwar Tŷ

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 Cae Gwar Tŷ (SN 656 640)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau y Myrddyn Phillips

The name the hill is now listed by is Cae Gwar Tŷ and this was derived from the Tithe map, and it is adjoined to the Mynydd Bach group of hills, which are situated in the western part of South Wales (Region B, Sub-Region B1), and it is positioned with the A485 road to its west and south, and a minor road to its east, and has the town of Tregaron towards the south south-east.

When the original 200m 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 266m based on the spot height adjoined to a triangulation pillar positioned at SN 65517 64195 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

One of the mapping resources now available online is on the Magic Maps website which hosts an interactive map originated from Ordnance Survey data.  Until recently this mapping had many spot heights not on other publicly available maps and for this hill it had a 266m spot height positioned at SH 656 640. 

Extract from the interactive mapping hosted on 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.

The height produced by LIDAR analysis to the summit of this hill is 266.1m positioned at SN 65639 64649, and this position 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 266.1m which is positioned at SN 65639 64649, 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 160 metres south-eastward from where the previously listed summit is positioned.  However, this position is in close proximity to where the 266m spot height appeared on the interactive mapping hosted on the Magic Maps website. 

 

The full details for the hill are:

Group:  Mynydd Bach 

Name:  Cae Gwar Tŷ 

OS 1:50,000 map:  146

Summit Height:  266.1m (LIDAR) 

Summit Grid Reference (New Position):  SN 65639 64049 (LIDAR) 

Bwlch Height:  c 232m (interpolation) 

Bwlch Grid Reference:  SN 64663 64467 (interpolation) 

Drop:  c 34m (LIDAR summit and interpolated bwlch) 

 

Myrddyn Phillips (December 2022)

 

Mapping Mountains - Summit Relocations - 200m Twmpau

Banc Pontfaen (SN 564 484) - 28th summit relocation

Hill Reclassifications post for Banc Pontfaen

Significant Name Changes post for Banc Pontfaen

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 Banc Pontfaen (SN 564 484)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Banc Pontfaen and this was derived from the Ordnance Survey Draft Surveyors Map, and it is adjoined to the Mynydd Bach group of hills, which are situated in the western part of South Wales (Region B, Sub-Region B1), and it is positioned with the A482 road to its north-east, and a minor road to its south-west and east, and has the town of Llanbedr Pont Steffan (Lampeter) towards the east south-east.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, the qualifying hill was listed with a summit height of 224m 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 SN 550 487. 

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

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and its summit relocated to SN 564 484 and listed with an estimated c 32m of drop, based on an estimated c 226m summit height and an estimated c 194m bwlch height, with both heights based on interpolation of 5m contouring that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage 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 Tyn Ffynnon (224.3m at SN 549 487 [on left] and Banc Pontfaen (225.6m at SN 564 484 [on right])

The height produced by LIDAR analysis to the summit of this hill is 225.6m positioned at SN 56441 48477, as opposed to where the 224m spot height appears which LIDAR gives as 224.3m positioned at SN 54956 48738, and this position 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 225.6m which is positioned at SN 56441 48477, 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 1500 metres eastward from where the previously listed summit is positioned. 

 

The full details for the hill are: 

Group:  Mynydd Bach 

Name:  Banc Pontfaen 

OS 1:50,000 map:  146

Summit Height:  225.6m (LIDAR) 

Summit Grid Reference (New Position):  SN 56441 48477 (LIDAR) 

Bwlch Height:  194.2m (LIDAR) 

Bwlch Grid Reference:  SN 55294 49452 (LIDAR) 

Drop:  31.4m (LIDAR) 

 

Myrddyn Phillips (December 2022)

Mapping Mountains - Summit Relocations - 200m Twmpau

Gwastadedd (SN 629 594) - 27th summit relocation

Significant Name Changes post for Gwastadedd

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 Gwastadedd (SN 629 594)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Gwastadedd and this was derived from the Tithe map, and it is adjoined to the Mynydd Bach group of hills, which are situated in the western part of South Wales (Region B, Sub-Region B1), and it is positioned with a minor road to its north-west, the B4342 road to its south-west and the B4578 road to its east, and has the town of Tregaron towards the east. 

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

When the original 200m 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 c 220m based on the uppermost contour that appears on the Ordnance Survey 1:25,000 Explorer map which is positioned at SN 633 592, with an accompanying note stating; Two points of same height – other at SN 630594. 

The first LIDAR summit image of Gwastadedd

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 second LIDAR summit image of Gwastadedd

LIDAR analysis gives the highest ground on this hill as 222.2m positioned at SN 62925 59399.  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. 

The third LIDAR summit image of Gwastadedd

The height produced by LIDAR analysis to the natural summit of this hill is 222.1m positioned at SN 62929 59415, 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 to when the high point of the hill 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 222.1m and this is to the natural summit of the hill which is positioned at SN 62929 59415, 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 16 metres northward from where the high point of the raised field boundary is positioned. 

 

The full details for the hill are:

Group:  Mynydd Bach 

Name:  Gwastadedd 

OS 1:50,000 map:  146

Summit Height:  222.1m (LIDAR) 

Summit Grid Reference (New Position):  SN 62929 59415 (LIDAR) 

Bwlch Height:  185.9m (LIDAR) 

Bwlch Grid Reference:  SN 63680 59433 (LIDAR) 

Drop:  36.2m (LIDAR)

 

Myrddyn Phillips (November 2022)

Mapping Mountains - Summit Relocations - 200m Twmpau

Cae Pen Crug (SN 654 592) - 26th summit relocation

Hill Reclassifications post for Cae Pen Crug

Significant Height Revisions post for Cae Pen Crug

Significant Name Changes post for Cae Pen Crug

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 Cae Pen Crug (SN 654 592)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Cae Pen Crug and this was derived from the Tithe map, and it is adjoined to the Mynydd Bach group of hills, which are situated in the western part of South Wales (Region B, Sub-Region B1), and it is positioned with a minor road to its north, the B4578 road to its west, the B4342 road to its south and the A485 road to its east, and has the town of Tregaron towards the east.

When the original 200m 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 224m 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 SN 655 590. 

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 Cae Pen Crug (SN 654 592)

The height produced by LIDAR analysis to the summit of this hill is 229.1m positioned at SN 65493 59251, and this position 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 229.1m which is positioned at SN 65493 59251, 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 190 metres north-westward from where the previously listed summit is positioned. 

 

The full details for the hill are:

Group:  Mynydd Bach 

Name:  Cae Pen Crug 

OS 1:50,000 map:  146

Summit Height:  229.1m (LIDAR) 

Summit Grid Reference (New Position):  SN 65493 59251 (LIDAR) 

Bwlch Height:  194.2m (LIDAR) 

Bwlch Grid Reference:  SN 65231 59601 (LIDAR) 

Drop:  34.9m (LIDAR) 

 

Myrddyn Phillips (October 2022)

 

 

Mapping Mountains - Summit Relocations - 200m Twmpau

Banc (SN 638 606) - 25th summit relocation

Significant Name Changes post for Banc

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 Banc (SN 638 606)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Banc and this was derived from the Tithe map, and it is adjoined to the Mynydd Bach group of hills, which are situated in the western part of South Wales (Region B, Sub-Region B1), and it is positioned with a minor road and the B4577 road to its north-west, a minor road and the B4576 road to its west, a minor road and the B4342 road to its south and the B4578 road to its east, and has the town of Tregaron towards the east.

When the original 200m 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 247m based on the spot height adjoined to a triangulation pillar that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and which is positioned at SN 636 602. 

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 (SN 638 606)

The height produced by LIDAR analysis to the summit of this hill is 247.5m positioned at SN 63875 60609, and this position in relation to that of the triangulation pillar 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 247.5m which is positioned at SN 63875 60609, 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 north-eastward from where the previously listed summit is positioned. 

 

The full details for the hill are:

Group:  Mynydd Bach 

Name:  Banc 

OS 1:50,000 map:  146

Summit Height:  247.5m (LIDAR) 

Summit Grid Reference (New Position):  SN 63875 60609 (LIDAR) 

Bwlch Height:  184.8m (LIDAR) 

Bwlch Grid Reference:  SN 65417 60139 & SN 65423 60135 (LIDAR) 

Drop:  62.6m (LIDAR)

 

Myrddyn Phillips (October 2022)

 

 

 

Mapping Mountains - Summit Relocations - 200m Twmpau

Cwm Gwenyn (SN 619 611) - 24th summit relocation

Significant Name Changes post for Cwm Gwenyn

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 Cwn Gwenyn (SN 619 611)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Cwm Gwenyn and this was derived from the Tithe map, and it is adjoined to the Mynydd Bach group of hills, which are situated in the western part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its west and east, the B4577 road to its north and the B4342 road to its south, and has the town of Tregaron towards the east.

When the original 200m 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 209m based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map which is positioned at SN 619 611. 

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 207.4m positioned at SN 61917 61105.  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 Cwm Gwenyn (SN 619 611)

The height produced by LIDAR analysis to the natural summit of this hill is 207.6m positioned at SN 61917 61104, 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 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 207.6m and this is to the natural summit of the hill which is positioned at SN 61917 61109, this position is not given a spot height on the contemporary Ordnance Survey 1:25,000 Explorer map, and is approximately 4 metres north from where the high point of the raised field boundary is positioned. 

 

The full details for the hill are:

Group:  Mynydd Bach 

Name:  Cwm Gwenyn 

OS 1:50,000 map:  146

Summit Height:  207.6m (LIDAR) 

Summit Grid Reference (New Position):  SN 61917 61109 (LIDAR) 

Bwlch Height:  172.5m (LIDAR) 

Bwlch Grid Reference:  SN 62494 62171 (LIDAR) 

Drop:  35.1m (LIDAR)

 

Myrddyn Phillips (October 2022)

 

Mapping Mountains - Summit Relocations - 200m Twmpau

Moel y Crio (SJ 199 696) - 23rd summit relocation

Survey post for Moel y Crio

Hill Reclassifications post for Moel y Crio

Significant Height Revisions post for Moel y Crio

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from a Trimble GeoXH 6000 survey conducted by Myrddyn Phillips with assistance from Mark Trengove.

 

Moel y Crio (SJ 199 696)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

 

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Moel y Crio, 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 encircled by minor roads with the B5123 road farther to its east, and has the town of Yr Wyddgrug (Mold) towards the south-east. 

When the original 200m 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 14m of drop, based on the 292m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map at SJ 20083 69520 and an estimated c 278m bwlch height, based on interpolation of 5m contouring between 275m – 280m 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 the Trimble GeoXH 6000 survey that the details for this hill could be accurately re-assessed.  The summit height produced by this survey is 297.5m and is positioned at SJ 19988 69614, 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 Moel y Crio

Therefore, the summit height produced by the Trimble GeoXH 6000 survey is 297.5m and this is positioned at SJ 19988 69614, 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 north-westward from where the previously listed summit is positioned. 

 

The full details for the hill are:

Group:  Moel y Gamelin 

Name:  Moel y Crio 

OS 1:50,000 map:  116

Summit Height:  297.5m (converted to OSGM15) 

Summit Grid Reference (New Position):  SJ 19988 69614 

Bwlch Height:  276.8m (converted to OSGM15) 

Bwlch Grid Reference:  SJ 20406 69385 

Drop:  20.7m

 

Myrddyn Phillips (September 2022)

 

Mapping Mountains - Summit Relocations - 200m Twmpau

Pen y Ddinas (SN 627 357) - 22nd summit relocation

Significant Height Revisions post for Pen y Ddinas

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau 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 Pen y Ddinas (SN 627 357)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau 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 Myrddy Phillips

The name the hill is listed by is Pen y Ddinas 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 a minor road to its north, the B4337 road to its south-west and the B4302 road to its east, and has the village of Llansawel towards the north-west.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was listed with a c 200m summit height based on the uppermost contour on the contemporary Ordnance Survey 1:25,000 Explorer map.

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 53m drop, based on an estimated c 207m summit height and an estimated c 154m bwlch height, with both heights based on interpolation of 10m contouring that appear on the contemporary Ordnance Survey 1:25,000 Explorer map.  The summit height was subsequently re-evaluated and listed as an estimated c 203m positioned at SN 62927 35808. 

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 y Ddinas (SN 627 357)

The summit height produced by LIDAR analysis is 230.9m and is positioned at SN 62756 35746, 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 230.9m and this is positioned at SN 62756 35746, 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 170 metres westward from where the previously listed summit is positioned.  

 

The full details for the hill are:

Group:  Mynydd Pencarreg

Name:  Pen y Ddinas

OS 1:50,000 map:  146

Summit Height:  230.9m (LIDAR)

Summit Grid Reference (New Position):  SN 62756 35746 (LIDAR)

Bwlch Height:  153.2m (LIDAR)

Bwlch Grid Reference:  SN 62239 35477 (LIDAR)

Drop:  77.7m (LIDAR)

Dominance:  33.63% (LIDAR)

 

Myrddyn Phillips (June 2022)

Mapping Mountains - Summit Relocations - 200m Twmpau

Y Lan (SN 737 340) - 21st summit relocation

Significant Name Changes post for Y Lan

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau 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 Y Lan (SN 737 340)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau 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 Y Lan and this was derived from the Tithe map, and it is adjoined to the Mynydd Mallaen 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 and west, the A482 road farther to its west and the A40 road to its south-east, and has the town of Llanymddyfri (Llandovery) towards the east. 

When the original Welsh 200m P30 list was published on Geoff Crowder’s v-g.me website, this hill was listed with a 244m summit height, based on the spot height adjoined to a triangulation pillar that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and which is positioned at SN 73903 33991. 

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 Lan (SN 737 340)

The summit height produced by LIDAR analysis is 244.4m and is positioned at SN 73776 34010, 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 244.4m and this is positioned at SN 73776 34010, 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 130 metres westward from where the previously listed summit is positioned.

 

The full details for the hill are:

Group:  Mynydd Mallaen

Name:  Y Lan

OS 1:50,000 map:  146, 160

Summit Height:  244.4m (LIDAR) 

Summit Grid Reference (New Position):  SN 73776 34010 (LIDAR) 

Bwlch Height:  135.75m (LIDAR) 

Bwlch Grid Reference:  SN 74333 34767 (LIDAR) 

Drop:  108.6m (LIDAR) 

Dominance:  44.45% (LIDAR) 

 

Myrddyn Phillips (March 2022)

 

Mapping Mountains - Summit Relocations - 200m Twmpau

Fan (SN 672 315) - 20th summit relocation

Significant Height Revisions post for Fan

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau 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 Fan (SN 672 315)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau 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 Fan, and it is adjoined to the Mynydd Mallaen 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, north-east and south and the B4302 road to the south-west, and has the village of Llanwrda towards the east. 

When the original Welsh 200m P30 list was published on Geoff Crowder’s v-g.me website, this hill was listed with a 265m summit height, based on the spot height adjoined to a triangulation pillar that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and which is positioned at SN 67516 31466. 

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

Since the original publication of the Welsh P30 lists on Geoff Crowder’s v-g.me website there have been a number of 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 were digitally updated such as the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map, whilst others are current and digitally updated such as the interactive mapping 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 Ordnance Survey maps and for this hill it had a 267m summit spot height positioned at SN 67222 31598. 

Another of the mapping resources now available online is the Magic Maps website which hosts an interactive map originated from Ordnance Survey data.  This mapping also shows a 267m spot height in the same vicinity as the spot height on the Interactive Coverage Map. 

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 Fan (SN 672 315)

The summit height produced by LIDAR analysis is 268.7m and is positioned at SN 67223 31597, 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 268.7m and this is positioned at SN 67223 31597, 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 310 metres north-westward from where the previously listed summit is positioned.  

 

The full details for the hill are:

Group:  Mynydd Mallaen

Name:  Fan

OS 1:50,000 map:  146

Summit Height:  268.7m (LIDAR) 

Summit Grid Reference (New Position):  SN 67223 31597 (LIDAR) 

Bwlch Height:  175.4m (LIDAR) 

Bwlch Grid Reference:  SN 67061 31937 (LIDAR) 

Drop:  93.3m (LIDAR) 

Dominance:  34.71% (LIDAR) 

 

Myrddyn Phillips (March 2022)

Mapping Mountains - Summit Relocations - 200m Twmpau

Cefn Bwlch Cennant (SN 802 424) - 19th summit relocation

Hill Reclassifications post for Cefn Bwlch Cennant

Significant Name Changes post for Cefn Bwlch Cennant

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 Bwlch Cennant (SN 802 424)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Cefn Bwlch Cennant and this was derived from the Tithe map, and it is adjoined to the Drygarn Fawr group of hills, which are situated in the central part of the South Wales Region (Region B, Sub-Region B1), and it is positioned encircled by minor roads, with the A483 road farther to its south-east, and has the town of Llanymddyfri (Llandovery) towards the south south-west. 

When the original 200m 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 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 an estimated c 29m of drop, based on an estimated c 283m summit height and an estimated c 254m bwlch height, with both heights 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

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 282m summit spot height and a 251m bwlch spot height, with these values giving this hill 31m of drop. 

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 Bwlch Cennant (SN 802 424)

The height produced by LIDAR analysis for the remaining natural summit is 281.168m and is positioned at SN 80249 42439, with LIDAR analysis also giving a raised field boundary positioned at SN 80245 42451 a height of 281.603m, 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 281.2m and this is positioned at SN 80249 42439, this position is relatively close to where the 282m spot height appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map and importantly to the remaining natural summit of this hill as opposed to the slightly higher raised field boundary.

 

The full details for the hill are: 

Group:  Drygarn Fawr 

Name:  Cefn Bwlch Cennant 

OS 1:50,000 map:  147, 160

Summit Height:  281.2m (LIDAR) 

Summit Grid Reference (New Position):  SN 80249 42439 (LIDAR) 

Bwlch Height:  250.55m (LIDAR) 

Bwlch Grid Reference:  SN 80310 42683 (LIDAR) 

Drop:  30.6m (LIDAR) 

 

Myrddyn Phillips (January 2022)

 

Mapping Mountains - Summit Relocations - 200m Twmpau

Pt. 212.2m (SJ 304 530) - 18th summit relocation

Survey post for Pt. 212.2m

Significant Name Changes post for Pt. 212.2m

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 bwlch analysis and a Trimble GeoXH 6000 summit survey conducted by Myrddyn Phillips. 

The summit field of Pt. 212.2m (SJ 304 530)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The hill is being listed by the point (Pt. 212.2m) 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 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 the B5433 road to its north and minor roads to its west and south, and has the village of Bryn-teg towards the south. 

When the original 200m 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 211m based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map and which is positioned at SJ 301 537. 

Extract from the Ordnance Survey 1:25,000 Explorer 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 a 213m summit spot height positioned at SJ 30407 53076, this is 2m higher than the previously listed summit height of 211m, and this comes within the Summit Relocations used within this page heading, and 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. 212.2m (SJ 304 530)

Therefore, the summit height produced by the Trimble GeoXH 6000 survey is 212.2m with the same 212.191m height produced at two different positions at SJ 30413 53067 and SJ 30417 53061, these positions are not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map but do match the approximate position of the 213m spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map, and they are approximately 650 metres southward from where the previously listed summit is positioned.

 

The full details for the hill are: 

Group:  Moel y Gamelin 

Name:  Pt. 212.2m 

OS 1:50,000 map:  117

Summit Height:  212.2m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference (New Position):  SJ 30413 53067 & SJ 30417 53061 (Trimble GeoXH 6000) 

Bwlch Height:  176.9m (LIDAR) 

Bwlch Grid Reference:  SJ 29817 53587 (LIDAR) 

Drop:  35.3m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (December 2021)

Mapping Mountains - Summit Relocations - 200m Twmpau

Coed Ffridd Fawr (SH 869 033) - 17th summit relocation

Hill Reclassifications post for Coed Ffridd Fawr

Significant Name Changes post for Coed Ffridd Fawr

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill initiated 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 Coed Ffridd Fawr (SH 869 033)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Coed Ffridd Fawr 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 positioned with a minor road to its north and the A470 road to its south, and has the village of Llanbryn-mair towards the east south-east. 

When the original 200m 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 category and it was listed with a summit height of 242m based on a spot height that appears on the Ordnance Survey 1:25,000 Explorer map positioned just to the north of a boundary fence on open hillside at SH 869 033.

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 Coed Ffridd Fawr (SH 869 033)

LIDAR analysis confirms the highest part of this hill to be positioned in forestry that has recently been felled and is a part of Coed Ffridd Fawr, this comes within the Summit Relocations used within this page heading, and 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 244.0m and this is positioned at SH 86944 03372, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and although not a dramatic summit relocation in distance, it is a significant summit relocation from open hillside to being positioned in a recently felled conifer plantation.

 

The full details for the hill are: 

Group:  Carnedd Wen 

Name:  Coed Ffridd Fawr 

OS 1:50,000 map:  135, 136

Summit Height:  244.0m (LIDAR) 

Summit Grid Reference (New Position):  SH 86944 03372 (LIDAR) 

Bwlch Height:  213.5m (LIDAR) 

Bwlch Grid Reference:  SH 87416 03786 (LIDAR) 

Drop:  30.5m (LIDAR) 

 

Myrddyn Phillips (November 2021)

Mapping Mountains - Summit Relocations - 200m Twmpau

Ffridd Cae Crydd (SN 749 976) - 16th summit relocation

Survey post for Ffridd Cae Crydd

Hill Reclassifications post for Ffridd Cae Crydd

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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. 

Ffridd Cae Crydd (SN 749 976) on centre left and Ffridd Eithaf (SN 745 977) on the right

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Ffridd Cae Crydd 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 A489 road to its north and minor roads to its west, south and east, and has the town of Machynlleth towards the north. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, the qualifying P30 hill was listed as Ffridd Eithaf (SN 745 977) with a summit height of 272m, based on the spot height that appears on the contemporary Ordnance Survey 1:25,000 Explorer map. 

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

When the listing that became known as The Welsh P15s was being compiled, Ffridd Cae Crydd was included in the P14 sub list with an estimated c 14m of drop, based on an estimated c 271m summit height and an estimated c 257m bwlch height, with both heights based on interpolation of 10m contouring that appear on 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 Ffridd Cae Crydd on right and Ffridd Eithaf on left

LIDAR analysis confirms Ffridd Cae Crydd as higher than Ffridd Eithaf and as the summit of both hills has now been surveyed with the Trimble GeoXH 6000, it is this result that is being prioritised for listing purposes. 

LIDAR summit image of Ffridd Cae Crydd on right and Ffridd Eithaf on left

The Trimble GeoXH 6000 survey result for each summit is given below: 

 

Ffridd Cae Crydd:  272.289m at SN 74910 97692 

Ffridd Eithaf:  272.175m at SN 74578 97750 

 

As LIDAR analysis confirms Ffridd Cae Crydd as higher than Ffridd Eithaf, and as this has now been substantiated by the Trimble GeoXH 6000 survey, this comes within 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 Ffridd Cae Crydd

The Trimble GeoXH 6000 gathering data at the summit of Ffridd Eithaf

Therefore, the summit height produced by the Trimble GeoXH 6000 survey is 272.3m and this is positioned at SN 74910 97692, 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 330 metres eastward from where the previously listed summit is positioned.

 

The full details for the hill are:

Group:  Pumlumon

Name:  Ffridd Cae Crydd 

OS 1:50,000 map:  135

Summit Height:  272.3m (converted to OSGM15, Trimble GeoXH 6000)  

Summit Grid Reference (New Position):  SN 74910 97692 (Trimble GeoXH 6000) 

Bwlch Height:  232.8m (LIDAR) 

Bwlch Grid Reference:  SN 75107 97628 (LIDAR) 

Drop:  39.4m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

Myrddyn Phillips (October 2021)

 

 

Mapping Mountains - Summit Relocations - 200m Twmpau

Llwynderw Hill (SJ 196 036) - 15th summit relocation

Survey post for Llwynderw Hill

Significant Name Changes post for Llwynderw Hill

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 Llwynderw Hill (SJ 196 036)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub category entitled the 200m Sub-Twmpau consisting of all Welsh hills at or above 200m and below 300m in height that have 20m or more and below 30m of drop.  With the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Llwynderw Hill 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 positioned with minor roads to its north, west and south and the A483 road to its south-east, and has the town of Y Trallwng (Welshpool) towards the north-east. 

When the original 200m 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, and listed with a 238m 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

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 shows the ground on a raised field boundary to be the highest on the hill, however as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill in the listings I author.  LIDAR analysis also shows the position of the highest remaining natural ground and this has now been surveyed with the Trimble GeoXH 6000 and it is this result that is being prioritised for this hill. 

LIDAR summit image of Llwynderw Hill

The summit height and position produced by the Trimble GeoXH 6000 survey is 237.9m at SJ 19600 03662, and this position in relation to the raised field boundary shown by LIDAR analysis 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 natural summit of Llwynderw Hill

Therefore, the new listed summit height for this hill is 237.9m and is positioned at SJ 19600 03662, this position is not given a spot height on contemporary Ordnance Survey maps and is in a different field to where the 238m spot height is positioned on the Ordnance Survey 1:25,000 Explorer map and is approximately seven metres east north-eastward from where LIDAR gives the high point of the raised field boundary. 

 

The full details for the hill are:

Group:  Carnedd Wen

Name:  Llwynderw Hill

OS 1:50,000 map:  136

Summit Height:  237.9m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference (New Position):  SJ 19600 03662 (Trimble GeoXH 6000) 

Bwlch Height:  159.7m (LIDAR) 

Bwlch Grid Reference:  SJ 18827 03989 (LIDAR) 

Drop:  78.3m (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

Myrddyn Phillips (June 2021)

Mapping Mountains - Summit Relocations - 200m Twmpau

Banc y Maen Rochorlem (SN 675 691) - 14th summit relocation

Survey post for Banc y Maen Rochorlem

Hill Reclassifications post for Banc y Maen Rochorlem

Significant Height Revisions post for Banc y Maen Rochorlem

Significant Name Changes post for Banc y Maen Rochorlem

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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. 

The summit of Banc y Maen Rochorlem (SN 675 691)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub category entitled the 200m Sub-Twmpau consisting of all Welsh hills at or above 200m and below 300m in height that have 20m or more and below 30m of drop.  With the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Banc y Maen Rochorlem and this was derived from the Tithe map, and it is adjoined to the Elenydd group of hills which are situated in the central part of the Mid and West Wales Region (Region B, Sub-Region B2), and it is positioned with the A485 road to its west, the B4340 road to its north and east, and has the village of Lledrod towards the west north-west. 

When the original 200m 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 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 28m of drop, based on an estimated c 296m summit height and an estimated c 268m bwlch height, with both heights based on interpolation of 10m contouring that appear on the Ordnance Survey 1:25,000 Explorer map.  With an adjacent hill now listed as Cae Pen y Maen (SN 656 694) given a summit height of 297m which was based on the spot height that appears on contemporary Ordnance Survey 1:25,000 Explorer maps. 

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 a 299m spot height was given on the area of its summit and as this is higher than the 297m spot height given Cae Pen y Maen the bylchau were swapped and each hill was reclassified. 

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 Banc y Maen Rochorlem

LIDAR analysis and an on-site visit shows the ground on a raised field boundary which comprises a grassed over stone and earth embankment to be the highest on the hill, however as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill in the listings I author.  The on-site visit determined the position of the highest remaining natural ground and this has now been surveyed with the Trimble GeoXH 6000 and it is this result that is being prioritised for this hill. 

The Trimble GeoXH 6000 gathering data at the summit of Banc y Maen Rochorlem

The summit height and position produced by the Trimble GeoXH 6000 survey is 299.3m at SN 67513 69184, 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 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 new listed summit height for this hill is 299.3m and is positioned at SN 67513 69184, this position compliments that of the 299m spot height but is taken to the remaining natural ground and not to the man-made raised field boundary embankment.

 

The full details for the hill are:

Group:  Elenydd

Name:  Banc y Maen Rochorlem 

OS 1:50,000 map:  135

Summit Height:  299.3m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference (New Position):  SN 67513 69184 (Trimble GeoXH 6000) 

Bwlch Height:  206.2m (LIDAR) 

Bwlch Grid Reference:  SN 69578 68344 (LIDAR) 

Drop:  93.1m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (April 2021)

 

Mapping Mountains - Summit Relocations - 200m Twmpau

Banc (SN 674 702) - 13th summit relocation

Survey post for Banc

Significant Name Changes post for Banc

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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. 

Banc (SN 674 702)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub category entitled the 200m Sub-Twmpau consisting of all Welsh hills at or above 200m and below 300m in height that have 20m or more and below 30m of drop.  With the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Banc and this was derived from local enquiry, and it is adjoined to the Elenydd group of hills which are situated in the central part of the Mid and West Wales Region (Region B, Sub-Region B2), and it is positioned with the A485 road to its west, the B4340 road to its north and east, and has the village of Lledrod towards the west. 

When the original 200m 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, and listed with a 289m 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

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. 

Gathering data at the remaining natural high point of Banc - 289.449m at SN 67427 70214

LIDAR analysis shows the ground on a raised field boundary which comprises a grassed over stone and earth embankment to be the highest on the hill, however as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill in the listings I author.  LIDAR analysis also shows the position of the highest remaining natural ground and this has now been surveyed with the Trimble GeoXH 6000 and it is this result that is being prioritised for this hill. 

Gathering data at the high point of the raised field embankment - 290.179m at SN 67410 70166

The summit height and position produced by the Trimble GeoXH 6000 survey is 289.4m at SN 67427 70214, and this position in relation to the raised field boundary shown by LIDAR analysis 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 new listed summit height for this hill is 289.4m and is positioned at SN 67427 70214, this position is not given a spot height on contemporary Ordnance Survey maps and is in a different field to where the 289m spot height is positioned and is approximately 50 metres northward from where LIDAR gives the high point of the raised field boundary.

 

The full details for the hill are:

Group:  Elenydd

Name:  Banc

OS 1:50,000 map:  135

Summit Height:  289.4m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference (New Position):  SN 67427 70214 (Trimble GeoXH 6000) 

Bwlch Height:  234.4m (LIDAR) 

Bwlch Grid Reference:  SN 67366 69677 (LIDAR) 

Drop:  55.05m (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

Myrddyn Phillips (April 2021)

 

Mapping Mountains - Summit Relocations - 200m Twmpau

Stingwern Wood (SJ 145 000) - 12th summit relocation

Survey post for Stingwern Wood

Significant Height Revisions post for Stingwern Wood

Significant Name Changes post for Stingwern Wood

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 a Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Stingwern Wood (SJ 145 000)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub category entitled the 200m Sub-Twmpau consisting of all Welsh hills at or above 200m and below 300m in height that have 20m or more and below 30m of drop.  With the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Stingwern Wood, 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 B4390 road further to its north, the B4389 road further to its west and the A483 road further to its south-east, and has the village of Aberriw (Berriew) towards the east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website the qualifying hill was included in the main P30 list with a summit height of 251m positioned at SJ 154 997, which was taken from 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 accompanying sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 60m of drop, based on an estimated c 258m summit height and an estimated c 198m bwlch height, with both values based on interpolation of 10m contouring that appear on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, with the summit also relocated to SJ 145 000. 

The summit of this hill has now been surveyed with the Trimble GeoXH 6000, resulting in 260.0m at SJ 14514 00063 and this height 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 Stingwern Wood

Therefore, the new listed summit height for this hill is 260.0m and is positioned at SJ 14514 00063, 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 1km west north-westward from where the originally listed summit is positioned. 

 

The full details for the hill are:

Group:  Carnedd Wen

Name:  Stingwern Wood

OS 1:50,000 map:  136

Summit Height:  260.0m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference (New Position):  SJ 14514 00063 (Trimble GeoXH 6000) 

Bwlch Height:  c 198m (interpolation) 

Bwlch Grid Reference:  SJ 14414 00402 (interpolation) 

Drop:  c 62m (Trimble GeoXH 6000 summit and interpolated bwlch) 

 

Myrddyn Phillips (March 2021)

Mapping Mountains - Summit Relocations - 200m Twmpau

Parkhouse Rocks (SO 499 034) - 11th summit relocation

Significant Name Changes post for Parkhouse Rocks

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 Parkhouse Rocks (SO 499 034)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub category entitled the 200m Sub-Twmpau consisting of all Welsh hills at or above 200m and below 300m in height that have 20m or more and below 30m of drop.  With the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Parkhouse Rocks, and it is adjoined to the Gwent Is Coed group of hills which are situated in the south-eastern part of South Wales (Region C, Sub-Region C3), and it is encircled by minor roads with the B4293 road further to its north-west and the A466 road further to its east, and has the small community of Llanishen towards the west and the village of Llandogo towards the east north-east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website the qualifying hill was included in the main P30 list under the name of Ninewells Wood Top, and listed with a 274m summit height, based on the spot height that appears at SO 509 033 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 the old summit position

The summit height and position produced by LIDAR analysis is 276.1m at SO 49959 03439, and as this is higher than the previously listed summit positioned to the east it 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 new listed summit height for this hill is 276.1m and is positioned at SO 49959 03439, this position is not given a spot height on contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps and is 1,000 metres westward from where the previously listed summit is positioned.

 

The full details for the hill are:

Group:  Gwent Is Coed

Name:  Parkhouse Rocks

OS 1:50,000 map:  162

Summit Height:  276.1m (LIDAR) 

Summit Grid Reference (New Position):  SO 49959 03439 (LIDAR) 

Bwlch Height:  235.2m (LIDAR) 

Bwlch Grid Reference:  SO 50941 04537 (LIDAR) 

Drop:  40.9m (LIDAR)

 

Myrddyn Phillips (February 2021)

Mapping Mountains - Summit Relocations - 200m Twmpau

Field Above The House (SO 135 990) - 10th summit relocation

Survey Post for Field Above The House

Significant Name Changes post for Field Above The House

 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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. 

Field Above The House (SO 135 990)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub category entitled the 200m Sub-Twmpau consisting of all Welsh hills at or above 200m and below 300m in height that have 20m or more and below 30m of drop.  With the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Field Above The House 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 also the B4390 road to its north, the B4389 road to its west and the A483 road to its south-east, and has the village of Tregynon towards the west. 

When the original 200m 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, and listed with a 263m 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 the details for this hill were re-assessed and it was subsequently noted that the interactive mapping on the Magic Maps and the WalkLakes websites give this hill a 265m summit spot height. 

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 Field Above The House

LIDAR analysis shows the ground at the base of a raised field boundary to be the highest on the hill, however as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill in the listings I author.  LIDAR analysis also shows the position of the natural summit of this hill and this has now been surveyed with the Trimble GeoXH 6000 and it is this result that is being prioritised for this hill. 

The Trimble GeoXH 6000 gathering data at the summit of Field Above The House

The summit height and position produced by the Trimble GeoXH 6000 survey is 264.9m at SO 13508 99039, and this position in relation to the raised field boundary shown by LIDAR analysis 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 new listed summit height for this hill is 264.9m and is positioned at SO 13508 99039, this position is given a 263m spot height on contemporary Ordnance Survey 1:25,000 Explorer maps and is approximately nine metres from where LIDAR gives the high point of the raised field boundary. 

 

The full details for the hill are:

Group:  Carnedd Wen

Name:  Field Above The House

OS 1:50,000 map:  136

Summit Height:  264.9m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference (New Position):  SO 13508 99039 (Trimble GeoXH 6000) 

Bwlch Height:  220.0m (LIDAR) 

Bwlch Grid Reference:  SO 13331 98643 (LIDAR) 

Drop:  44.8m (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

Myrddyn Phillips (January 2021)

 

Mapping Mountains - Summit Relocations - 200m Twmpau

Cae Top (SJ 061 016) - 9th summit relocation

Survey post for Cae Top

Hill Reclassifications post for Cae Top

Significant Name Changes post for Cae Top

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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.

Cae Top (SJ 061 016)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub category entitled the 200m Sub-Twmpau consisting of all Welsh hills at or above 200m and below 300m in height that have 20m or more and below 30m of drop.  With the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Cae Top and this was derived from the Tithe map, 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 also the B4389 and B4390 roads to its east, and has the village of Adfa towards the south.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was not included in the accompanying 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-assessed and it was listed with 26m of drop, based on the 269m summit spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map and which is now presented on the mapping on the Magic Maps website and which is positioned at SJ 06183 01659, and the 243m bwlch spot height that appears on the Ordnance Survey 1:25,000 Explorer map.

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 analysis shows the ground at the base of a raised field boundary to be the highest on the hill, however as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill in the listings I author.  LIDAR analysis also shows the position of the natural summit of this hill and this has now been surveyed with the Trimble GeoXH 6000 and it is this result that is being prioritised for this hill.

LIDAR summit image of Cae Top

The summit height and position produced by the Trimble GeoXH 6000 survey is 268.8m at SJ 06132 01671, and this position in relation to the raised field boundary shown by LIDAR analysis 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.

The Trimble GeoXH 6000 gathering data at the summit of Cae Top

Therefore, the new listed summit height for this hill is 268.8m and is positioned at SJ 06132 01671, this position is given a spot height on the Magic Maps website and is approximately 50 metres from where LIDAR gives the high point of the raised field boundary.

 

The full details for the hill are:

Group:  Carnedd Wen

Name:  Cae Top

OS 1:50,000 map:  136

Summit Height:  268.8m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference (new position):  SJ 06132 01671 (Trimble GeoXH 6000)

Bwlch Height:  243.0m (LIDAR)

Bwlch Grid Reference:  SJ 06613 01642 (LIDAR)

Drop:  25.9m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Myrddyn Phillips (November 2020)

Mapping Mountains - Summit Relocations - 200m Twmpau

Cae Clofar Bach (SJ 069 007) - 8th summit relocation

Survey post for Cae Clofar Bach

Hill Reclassifications post for Cae Clofar Bach

Significant Name Changes post for Cae Clofar Bach

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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.

Cae Clofar Bach (SJ 069 007)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub category entitled the 200m Sub-Twmpau consisting of all Welsh hills at or above 200m and below 300m in height that have 20m or more and below 30m of drop.  With the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Cae Clofar Bach and this was derived from the Tithe map, 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 farther afield the B4389 and B4390 roads to its east, and has the village of Adfa towards the west north-west.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was not included in the accompanying Hills to be surveyed sub 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-assessed and it was listed with an estimated c 23m of drop, based on the 247m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and which is positioned at SJ 06961 00742 and an estimated c 224m bwlch height, with the latter based on interpolation of 5m contouring between 220m – 225m.

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 Cae Clofar Bach

LIDAR analysis shows the ground at the base of a raised field boundary to be the highest on the hill, however as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill in the listings I author.  LIDAR analysis also shows the position of the natural summit of this hill and this has now been surveyed with the Trimble GeoXH 6000 and it is this result that is being prioritised for this hill.

LIDAR summit image of Cae Clofar Bach

The summit height and position produced by the Trimble GeoXH 6000 survey is 246.1m at SJ 06945 00724, and this position in relation to the raised field boundary shown by LIDAR analysis 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.

The Trimble GeoXH 6000 gathering data at the natural summit of Cae Clofar Bach

Therefore, the new listed summit height for this hill is 246.1m and is positioned at SJ 06945 00724, this position is given a spot height on contemporary Ordnance Survey 1:25,000 Explorer maps and is approximately five metres from where LIDAR gives the high point of the raised field boundary.

 

The full details for the hill are:

Group:  Carnedd Wen

Name:  Cae Clofar Bach

OS 1:50,000 map:  136

Summit Height:  246.1m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference (new position):  SJ 06945 00724 (Trimble GeoXH 6000)

Bwlch Height:  224.3m (LIDAR)

Bwlch Grid Reference:  SJ 06767 00923 (LIDAR)

Drop:  21.8m (Trimble GeoXH 6000 summit and LIDAR bwlch)

For details on the Trimble GeoXH 6000 survey of this hill

Myrddyn Phillips (November 2020)

Mapping Mountains - Summit Relocations - 200m Twmpau

Crasty Frain (SO 109 983) - 7th summit relocation

Survey post for Crasty Frain

Hill Reclassifications post for Crasty Frain

Significant Height Revisions post for Crasty Frain

Significant Name Changes post for Crasty Frain

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill initially confirmed by LIDAR analysis instigated by Joe Nuttall who produced a summit analysis programme, and then by LIDAR analysis conducted initially by Jim Bloomer and subsequently by Myrddyn Phillips, with the summit later surveyed with the Trimble GeoXH 6000 and which was conducted by Myrddyn Phillips.

Crasty Frain (SO 109 983)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub category entitled the 200m Sub-Twmpau consisting of all Welsh hills at or above 200m and below 300m in height that have 20m or more and below 30m of drop.  With the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Crasty Frain and this was derived from the Tithe map, 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 positioned with a minor road to its north and the B4389 road to its south-west, and has the village of Tregynon towards the west north-west.

When the original 200m 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, as it was considered not to meet the criteria then used for the main P30 list, with its summit listed at SO 107 981 which compliments the position of the 253m spot height that appears on the Ordnance Survey 1:25,000 Explorer map. 

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

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 27m of drop, based on the 253m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 226m bwlch height, with the latter based on interpolation of 10m contouring between 220m – 230m.

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 relocation of this hill 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.

LIDAR image of Crasty Frain

This spreadsheet is being evaluated by a number of people, and for this particular hill it was Jim Bloomer who initially assessed this hill’s data against that produced via LIDAR.  Myrddyn Phillips then evaluated the details for this hill via LIDAR analysis and confirmed its summit height and position and hence its relocation and reclassification to 200m Twmpau status.  The summit of this hill has now been surveyed with the Trimble GeoXH 6000 and it is this evaluation on the hill and the subsequent survey that is being prioritised.

LIDAR summit image of Crasty Frain

The summit height and position produced by the Trimble GeoXH 6000 survey is 256.3m at SO 10995 98318, and this 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 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 new listed summit height for this hill is 256.3m and is positioned at SO 10995 98318, this position is not given a spot height on contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps but compliments the height and position of the 256m spot height that appears on the mapping available on the Magic Maps and the WalkLakes websites, and is approximately 250 metres north-westward from where the previously listed summit is positioned. 

The full details for the hill are:

Group:  Carnedd Wen

Name:  Crasty Frain

OS 1:50,000 map:  136

Summit Height:  256.3m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference (new position):  SO 10995 98318 (Trimble GeoXH 6000)

Bwlch Height:  226.1m (LIDAR)

Bwlch Grid Reference:  SO 10787 98754 (LIDAR)

Drop:  30.2m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Myrddyn Phillips (October 2020)

Mapping Mountains - Summit Relocations - 200m Twmpau

Church Hill Common (SO 517 105) - 6th summit relocation

Hill Reclassifications post for Church Hill Common

Significant Name Changes post for Church Hill Common

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, 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 Church Hill Common (SO 517 105)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub category entitled the 200m Sub-Twmpau consisting of all Welsh hills at or above 200m and below 300m in height that have 20m or more and below 30m of drop.  With the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The name the hill is listed by is Church Hill Common, and it is adjoined to the Gwent Is Coed group of hills which are situated in the south-eastern part of South Wales (Region C, Sub-Region C3), and it is positioned with the B4293 road and the A40 road to the west and the A466 road and the Afon Gwy (River Wye) to the east, and has the town of Trefynwy (Mounmouth) towards the north-west.

When the original 200m 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, as it was considered not to meet the criteria then used for the main P30 list, with its summit listed at SO 518 106 which compliments the position of the 232m 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 Church Hill Common (SO 517 105)

The summit height and position produced by LIDAR analysis is 232.7m at SO 51785 10565 and SO 51788 10566, and this 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 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 new summit height for this hill is 232.7m and is positioned at SO 51785 10565 and SO 51788 10566, 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 60 metres southward and in a different part of enclosed land from where the previously listed summit is positioned. 

The full details for the hill are:

Group:  Gwent Is Coed

Name:  Church Hill Common

OS 1:50,000 map:  162

Summit Height:  232.7m (LIDAR)

Summit Grid Reference (new position):  SO 51785 10565 & SO 51788 10566 (LIDAR)

Bwlch Height:  202.3m (LIDAR)

Bwlch Grid Reference:  SO 51524 10349 (LIDAR)

Drop:  30.3m (LIDAR)

Myrddyn Phillips (June 2020)

Mapping Mountains - Summit Relocations - 200m Twmpau

Coed y Bwnydd (SO 366 069) - 5th summit relocation

Significant Name Changes post for Coed y Bwnydd

Hill Reclassifications post for Coed y Bwnydd

Significant Height Revisions post for Coed y Bwnydd

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau 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 confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Coed y Bwnydd (SO 366 069)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop.

200m Twmpau 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 3rd 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 Coed y Bwnydd 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 the Afon Wysg (River Usk) and the B4598 road to its west, the A40 road to its north and the A449 road to its east, and has the village of Raglan towards the east north-east and the town of Brynbuga (Usk) towards the south south-east.

When the original 100m 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 under the name of Clytha Hill and listed with a 196m summit height, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map at SO 368 069.

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 on other publicly available Ordnance Survey maps and gives a second 196m spot height on the summit area of this hill and positioned at SO 367 069.  This additional 196m spot height also appears on Ordnance Survey data 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 Coed y Bwnydd (SO 366 069)

The summit height produced by LIDAR analysis is 201.4m positioned at SO 36613 06919.  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.

Therefore, the summit height produced by LIDAR analysis is 201.4m positioned at SO 36613 06919, this position is to an embankment that is a part of an ancient hill fort and this ground meets the criteria used within this list, and is approximately 120 metres westward from where the previous listed summit is positioned.

The full details for the hill are:

Group:  Mynyddoedd Duon

Name:  Coed y Bwnydd

OS 1:50,000 map:  161

Summit Height:  201.4m (LIDAR)

Summit Grid Reference (New Position):  SO 36613 06919 (LIDAR)

Bwlch Height:  59.4m (LIDAR)

Bwlch Grid Reference:  SO 39308 08901 (LIDAR)

Drop:  142.0m (LIDAR)

Dominance:  70.50%

Myrddyn Phillips (February 2020)

Mapping Mountains - Summit Relocations - 200m Twmpau

Mynydd Gelliwastad (SN 678 015) - 4th summit relocation

There has been a Summit Relocation to a hill that is listed in the 200m Twmapu and Y Trechol – The Dominant Hills of Wales, with the summit height, drop and status of the hill being confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Mynydd Gelliwastad

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

200m Twmpau - Welsh hills at or above 200m and below 300m in height with 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

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 Gelliwastad, and it is adjoined to the Mynydd Penlle’rcastell group of hills, which are situated in the western part of South Wales (Region C, Sub-Region C1), and has the Lower Clydach River, the B 4603 and the A 4067 towards its east and the M 4 towards its south, and has the village of Clydach towards its east.

As the summit of the hill is a part of designated open access land it can be approached from most directions with public footpaths accessing this land from the north and the west.

Prior to LIDAR analysis this hill was listed with c 100m of drop based on the 213m height given to a triangulation pillar positioned at SN 67799 01456 that appears on Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps, and an estimated bwlch height of c 113m based on interpolation of 5m contours between 110m – 115m.

Close up LIDAR image of the summit of Mynydd Gelliwastad

LIDAR image of the bwlch of Mynydd Gelliwastad

The summit height produced by LIDAR analysis is 213.9m at SS 67852 01598 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.

Extract from the Ordnance Survey 1:25,000 Explorer map showing the new summit position in relation to the old listed summit position at the trig pillar

The summit height produced by LIDAR analysis is 213.9m and is positioned at SN 67852 01598, this position is not given a spot height on contemporary Ordnance Survey maps but appears within an uppermost 210m contour ring.  This position is approximately 100 metres north from where the previously listed summit is positioned.  

The full details for the hill are:

Group:  Mynydd Penlle’rcastell

Name:  Mynydd Gelliwastad

OS 1:50,000 map:  159

Summit Height:  213.9m (LIDAR)

Summit Grid Reference (new position):  SN 67852 01598 (LIDAR)

Bwlch Height:  114.8m (LIDAR)

Bwlch Grid Reference:  SN 67677 02435 (LIDAR)

Drop:  99.1m (LIDAR)

Dominance:  46.33% (LIDAR)

Myrddyn Phillips (January 2019)

Mapping Mountains - Summit Relocations - 200m Twmpau

Bwlch Clump (SJ 170 108) - 3rd summit relocation

Survey post for Bwlch Clump

Hill Reclassifications post for Bwlch Clump

Significant Name Changes post for Bwlch Clump
  

There has been a detwinning of summits that is being detailed as a Summit Relocation initiated by a survey with the Trimble GeoXH 6000 in the list of 200m Twmpau (thirty welsh metre prominences and upward) hills, with the following details being retrospective as the survey that resulted in this summit relocation was conducted on the 20^th January 2016.

The hill was originally included in the main 200m P30 list that appeared on Geoff Crowder’s v-g.me website as a single summit listed under the partly invented name of Pen y Bryn Wood (Bryn Wood being the name of the wood to the north-east of the originally listed hill’s summit), with its 262m summit listed at SJ 173 109 which is where this spot height appears on the Ordnance Survey 1:25,000 Explorer map.  The hill later gained a twin summit when the Ordnance Survey enlarged mapping hosted on the Geograph website became available, and which included a 262m spot height for the adjacent hill at SJ 170 108, which was named as Bwlch Clump on this map.  Therefore the main purpose of this survey was to ascertain which of the two summits is higher and separate their twin top status.

The hill is situated in the eastern part of the Carnedd Wen range of hills, and between the small communities of Meifod and Maesmawr, with access to the hill relatively easy as there are public footpaths to the west and east, although its summit does not appear on open access land, therefore permission to visit the high point should be sought.

The names of the two map heighted twin tops are Pt. 262.8m and Bwlch Clump, with the former point (Pt.) notation being used as a name for the hill does not exist on current maps, with the latter name appearing on the Ordnance Survey enlarged Geograph map.

Prior to the survey with the Trimble GeoXH 6000 this hill was listed as a twin top with each 262m map heighted summit appearing at SJ 173 109 and SJ 170 108 respectively.

The survey results for this once twin topped P30 are:

Pt . 262.8m

262.8m (converted to OSGM15) summit at SJ 17354 10914

243.5m (converted to OSGM15) bwlch at SJ 17190 10797

19.4m drop

Bwlch Clump

263.9m (converted to OSGM15) summit at SJ 17063 10813

234.9m (converted to OSGM15) bwlch at SJ 17089 10581

29.1m drop

Therefore the survey with the Trimble GeoXH 6000 confirms that Bwlch Clump is 1.1m higher than Pt. 262.8m, and therefore Bwlch Clump is now listed as the prioritised higher summit.

The full details for the hill are:

Cardinal Hill:  Carnedd Wen

Summit Height:  263.9m (converted to OSGM15)

Name:  Bwlch Clump

OS 1:50,000 map:  125

Summit Grid Reference (confirmed higher summit):  SJ 17063 10813

Drop:  29.1m (converted to OSGM15)

The Trimble GeoXH 6000 gathering data at the confirmed higher summit of Bwlch Clump, with the old twin topped summit of Pt. 262.8m in the background of this photograph

For details on the survey that confirmed the higher of the two map heighted twin tops of this hill please click {here}

Myrddyn Phillips (January 2016)

Mapping Mountains - Summit Relocations - 200m Twmpau

Winllan Hill (SJ 217 214) - 2nd summit rlocation 

First summit survey post for Winllan Hill

Second summit survey post for Winllan Hill 

Significant Height Revisions post for Winllan Hill


There has been a Summit Relocation to the 200m Twmpau (thirty welsh metre prominences and upward) due to a survey with the Trimble GeoXH 6000, with the following details being retrospective as the survey that resulted in this summit relocation was conducted over two days; on 28^{th /} 29^th  August 2015.

The first of this hill's two surveys was conducted in the company of Mark Trengove on the lower easterly hills of the Y Berwyn, above the small community of Llansanffraid-ym-Mechain which is situated just north-west of where the Afon Cain flows in to the Afon Efyrnwy (River Vyrnwy).

Prior to the survey with the Trimble GeoXH 6000 the hill was listed with an estimated c 48m of drop based on the current Ordnance Survey summit spot height of 216m and an estimated bwlch height of c 168m.

There is good access to the summit of the hill with a number of public footpaths converging on its high point from a variety of directions, with its summit positioned beside a fence and under a large overhanging tree, with the high point only a few metres from where a public footpath crosses the field that it is situated in.

The name of the hill is Winllan Hill and prior to the survey with the Trimble GeoXH 6000 the position of the summit was listed as that of its 216m spot height which is situated at SJ 21686 21409.  This position is placed on a slight rise which resembles part of an ancient earthen embankment associated with an old hill fort, and although there is evidence of these existing on neighbouring hills there is no evidence on current maps that one existed on Winllan Hill.

The position of the relocated summit is at SJ 21709 21460 and this is the top of a field with the high point situated under a large overhanging tree beside a fence that runs in an east – west direction over the summit.  This position is not given a spot height on current Ordnance Survey maps but the survey result produced with the Trimble gave it as 4.3m higher when compared to the position where the 216m spot height appears on current Ordnance Survey maps and approximately 50 metres northward from it.

The full details for the hill are:

Cardinal Hill:  Rhialgwm

Summit Height:  220.3m (converted to OSGM15)

Name:  Winllan Hill

OS 1:50,000 map:  126

Summit Grid Reference (New Position):  SJ 21709 21460

  

Drop:  c 52m

The Trimble GeoXH 6000 gathering data at the new summit position of Winllan Hill, with Mark (wearing blue top) standing on the old position of the summit in the left background of this photograph

For details on the survey that relocated the summit of this hill please click {here}

Myrddyn Phillips (August 2015)

Mapping Mountains - Summit Relocations - 200m Twmpau

Pen y Berth (SJ 081 127) - 1st summit relocation

Summit survey post for Pen y Berth

Bwlch survey post for Pen y Berth

Significant Height Revisions post for Pen y Berth
  

There has been a Summit Relocation to the 200m Twmpau (thirty welsh metre prominences and upward) list and also the Y Trichant - The Dominant Hills of Wales list due to a survey with the Trimble GeoXH 6000, and these details are retrospective as the survey that resulted in this summit relocation was conducted on 19^th October 2014.

The survey was conducted in the hills just to the east of the small community of Dolanog, with the hill positioned above the B4382 which is to its south, and above the Afon Efyrnwy which is to its north.

The hill was surveyed in the company of Mark Trengove on a day when the westerly showers were being pushed east; thankfully all missed us as we visited two hills over two separate walks.

The hill is named Pen y Berth, and its prioritised summit position was listed at SJ 080 127 as this is where its 282m summit spot height appears on the Ordnance Survey enlarged mapping hosted on the Geograph website.  This map also shows a twin 282m map heighted summit at SJ 083 127.

The position of the spot height at SJ 080 127 is immersed in a conifer plantation, whilst the position of the spot height at SJ 083 127 is on open ground with small deciduous trees growing near to it.  The latter position was surveyed with the Trimble GeoXH 6000 as was a position on the periphery of the conifer plantation that was visually higher than the remaining ground within the forestry.

The result of each survey appears below:

282m spot height at SJ 083 127 came to 283.7m (converted to OSGM15) at SJ 08322 12748

new summit position came to 287.5m (converted to OSGM15) at SJ 08126 12730

282m spot height at SJ 080 127 was not surveyed as its position was deemed lower compared to the new summit position

The position of the relocated summit is at SJ 08126 12730 and is the top of featureless ground under Larch trees, this is not given a spot height on current Ordnance Survey maps but the Trimble result gave it as 5.5m higher and approximately 80 metres eastward from where the westerly 282m map spot height is positioned on the ground.

The full details for the hill are:

Cardinal Hill:  Carreg y Big

Summit Height:  287.5m (converted to OSGM15)

Name:  Pen y Berth

OS 1:50,000 map:  125

Summit Grid Reference (New Position):  SJ 08126 12730 

Drop:  134.2m (converted to OSGM15)

Dominance:  46.68%

The Trimble GeoXH 6000 set up at the new summit position of Pen y Berth, with the old position of the prioritised summit approximately 80 metres behind the Trimble and further into the conifer plantation

For details on the survey that relocated the summit of this hill please click {here}

Myrddyn Phillips (October 2014)