Mapping Mountains - Significant Height Revisions - Y Trichant - The 300m Hills of Wales

Y Trichant – Significant Height Revisions

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

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

Mapping Mountains - Significant Height Revisions - Y Trichant

Llanfilo Camp (SO 113 327) - 58th significant height revision

Summit Relocations post for Llanfilo Camp

Significant Name Changes post for Llanfilo Camp

 

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

LIDAR image of Llanfilo Camp (SO 113 327)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is now listed by is Llanfilo Camp and this was derived from information supplied by Coflein, and it is adjoined to the Mynydd Epynt group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned encircled by minor roads, with the A38 road farther to its north and the B4560 road farther to its east, and has the town of Talgarth towards the east north-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a 310m summit height adjoined to a triangulation pillar positioned at SO 11359 32761 that appears on the contemporary 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 Llanfilo Camp (SO 113 327)

The summit height produced by LIDAR analysis is 310.4m and is positioned at SO 11352 32709, and as this position has no 310m contour on contemporary Ordnance Survey maps this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 310.4m and this was derived from LIDAR analysis, this is 0.4m higher than the previously listed summit height of 310m, which was based on the triangulation pillar positioned at SO 11359 32761.  But as no 310m contour appears at the new summit position it is 10.4m higher than the uppermost 300m contour. 

 

The full details for the hill are: 

Group:  Mynydd Epynt 

Name:  Llanfilo Camp 

OS 1:50,000 map:  161

Summit Height (New Height):  310.4m (LIDAR)                                                           

Summit Grid Reference:  SO 11352 32709 (LIDAR) 

Bwlch Height:  223.6m (LIDAR) 

Bwlch Grid Reference:  SO 09879 31998 (LIDAR) 

Drop:  86.8m (LIDAR) 

 

Myrddyn Phillips (April 2024)

Mapping Mountains - Significant Height Revisions - Y Trichant

Fforest Crychan (SN 848 405) - 57th significant height revision

Significant Name Changes post for Fforest Crychan

 

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

LIDAR image of Fforest Crychan (SN 848 405)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is now listed by is Fforest Crychan, and it is adjoined to the Mynydd Epynt group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned with a minor road to its north-east and the A483 road to its north-west, and has the town of Llanwrtyd towards the north north-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a non-interpolated c 340m summit height, based on the uppermost contour that appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

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

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 36m of drop, based on an estimated c 345m summit height and the 309m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.

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 Fforest Crychan (SN 848 405)

The summit height produced by LIDAR analysis is 348.9m and is positioned at SN 84822 40507, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 348.9m and this was derived from LIDAR analysis, this is 3.9m higher than the previously listed summit height of c 345m, which was based on interpolation of the uppermost 340m ring contour on the Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Mynydd Epynt 

Name:  Fforest Crychan 

OS 1:50,000 map:  147, 160

Summit Height (New Height):  348.9m (LIDAR)                                                           

Summit Grid Reference:  SN 84822 40507 (LIDAR) 

Bwlch Height:  309.3m (LIDAR) 

Bwlch Grid Reference:  SN 85385 41112 & SN 85384 41110 (LIDAR) 

Drop:  39.6m (LIDAR) 

 

Myrddyn Phillips (February 2024)

 

Mapping Mountains - Significant Height Revisions - Y Trichant

Rhos Ymryson (SN 460 499) - 56th significant height revision

Summit Relocations post for Rhos Ymryson

 

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

LIDAR image of Rhos Ymryson (SN 460 499)

The criteria for the two listings that this height revision applies to are:

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

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

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

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Rhos Ymryson, 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 B4338 road to its north-east, a minor road to its north-west and the A475 road to its south, and has the village of Llanwenog towards the south-east. 

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

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

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a 327m summit height, based on the spot height that appears on the contemporary Ordnance Survey 1:25,000 Explorer map and which is positioned at SN 459 500.  However, this height is given to the top of a covered reservoir, whilst the contemporary Ordnance Survey 1:50,000 Landranger map gives a 324m summit spot height, which conforms with the rounded up 1062ft (323.7m) height shown on the Ordnance Surveys series of Six-Inch maps. 

Extract from the Ordnance Survey series of Six-Inch maps

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

LIDAR summit image of Rhos Ymryson (SN 460 499)

The summit height produced by LIDAR analysis to the highest remaining natural ground on this hill is 323.3m and is positioned at SN 46032 49996, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 323.3m and this was derived from LIDAR analysis, this is 3.7m lower than the originally listed summit height of 327m, which was based on the spot height that appears on the contemporary Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Mynydd Bach 

Name:  Rhos Ymryson 

OS 1:50,000 map:  146

Summit Height (New Height):  323.3m (LIDAR)                                                           

Summit Grid Reference:  SN 46032 49996 (LIDAR) 

Bwlch Height:  162.6m (LIDAR) 

Bwlch Grid Reference:  SN 61745 57992 (LIDAR) 

Drop:  160.8m (LIDAR) 

Dominance:  49.72% (LIDAR) 

 

Myrddyn Phillips (December 2023)

  

Mapping Mountains - Significant Height Revisions - Y Trichant

Pt. 329.7m (SN 591 630) - 55th significant height revision

Hill Reclassifications post for Pt. 329.7m

Summit Relocations post for Pt. 329.7m

 

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

LIDAR image of Pt. 329.7m (SN 591 630)

The criteria for the list that this height revision applies to are:

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

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

The hill is being listed by the point (Pt. 329.7m) notation 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 B4576 road to its north-west, B4577 road to its south and a minor road to its east, and has the village of Llangeitho towards the south-east.

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

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

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 20m of drop, based on an estimated c 327m summit height and an estimated c 307m 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.

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. 

Extract from the interactive mapping hosted on the Magic Maps website

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 327m spot height positioned on the summit area of this hill at SN 59019 63010, resulting in its details being amended accordingly.

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

LIDAR summit image of Pt. 329.7m (SN 591 630)

The summit height produced by LIDAR analysis is 329.7m and is positioned at SN 59108 63024, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 329.7m and this was derived from LIDAR analysis, this is 2.7m higher than the previously listed summit height of 327m, which was based on the spot height that appeared on the interactive mapping hosted on the Magic Maps website. 

 

The full details for the hill are: 

Group:  Mynydd Bach 

Name:  Pt. 329.7m 

OS 1:50,000 map:  146

Summit Height (New Height):  329.7m (LIDAR)                                                           

Summit Grid Reference:  SN 59108 63024 (LIDAR) 

Bwlch Height:  306.9m (LIDAR) 

Bwlch Grid Reference:  SN 59361 63409 & SN 59359 63413 (LIDAR) 

Drop:  22.8m (LIDAR) 

 

Myrddyn Phillips (December 2023) 

Mapping Mountains - Significant Height Revisions - Y Trichant

Craig Fawr (SN 589 621) - 54th significant height revision

Hill Reclassifications post for Craig Fawr

 

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

LIDAR image of Craig Fawr (SN 589 621)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Craig Fawr, 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 encircled by minor roads, with the B4577 road farther to its north, the B4576 road to its west, the B4342 road farther to its south-east and the B4578 road farther to its east, and has the village of Llangeitho towards the south-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was 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 20m of drop, based on an estimated c 313m summit height and an estimated c 293m 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. 

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. 

Extract from the interactive mapping hosted on the Magic Maps website

One of the mapping resources now available online is the Magic Maps website which hosts an interactive map originated from Ordnance Survey data.  This mapping had a 315m spot height on the summit area of this hill, resulting in its drop value being amended to an estimated c 22m.

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 Craig Fawr (SN 589 621)

The summit height produced by LIDAR analysis is 315.2m and is positioned at SN 58922 62145, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 315.2m and this was derived from LIDAR analysis, this is 2.2m higher than the originally listed summit height of c 313m, which was based on interpolation of the uppermost 310m ring contour on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

 

The full details for the hill are: 

Group:  Mynydd Bach 

Name:  Craig Fawr 

OS 1:50,000 map:  146

Summit Height (New Height):  315.2m (LIDAR)                                                           

Summit Grid Reference:  SN 58922 62145 (LIDAR) 

Bwlch Height:  293.0m (LIDAR) 

Bwlch Grid Reference:  SN 58953 62291 (LIDAR) 

Drop:  22.2m (LIDAR) 

 

Myrddyn Phillips (November 2023)

 

Mapping Mountains - Significant Height Revisions - Y Trichant

Craig y Bwlch (SN 718 696) - 53rd significant height revision

Hill Reclassifications post for Craig y Bwlch

 

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

LIDAR image of Craig y Bwlch (SN 718 696)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Craig y Bwlch, and it is adjoined to the Carn yr Hyrddod group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B1), and it is positioned with the B4340 road to its west, a minor road to its south-east and the B4343 road to its east, and has the village of Ysbyty Ystwyth towards the north-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for the main P30 category, with an accompanying note stating; Automatically qualified until the top was quarried away.  350c on 1986 1:50000 map. 

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

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 27m of drop, based on an estimated c 342m summit height and an estimated c 315m bwlch height, with both heights based on interpolation of 10m contouring that appears on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the interactive mapping hosted on the WalkLakes website which has a better portrayal of contours and the height of this hill

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

LIDAR summit image of Craig y Bwlch (SN 718 696)

The summit height produced by LIDAR analysis is 350.3m and is positioned at SN 71860 69685, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 350.3m and this was derived from LIDAR analysis, this is 8.3m higher than the previously listed summit height of c 342m, which was based on interpolation of the uppermost 340m ring contour on the contemporary Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Carn yr Hyrddod 

Name:  Craig y Bwlch 

OS 1:50,000 map:  135, 147

Summit Height (New Height):  350.3m (LIDAR)                                                           

Summit Grid Reference:  SN 71860 69685 (LIDAR) 

Bwlch Height:  312.0m (LIDAR) 

Bwlch Grid Reference:  SN 71462 69797 (LIDAR) 

Drop:  38.3m (LIDAR) 

 

Myrddyn Phillips (October 2023)

Mapping Mountains - Significant Height Revisions - Y Trichant

Pen Llwyn Uchel (SN 517 387) - 52nd significant height revision

Summit Relocations post for Pen Llwyn Uchel

Significant Name Changes post for Pen Llwyn Uchel

 

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

LIDAR image of Pen Llwyn Uchel (SN 517 387)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Pen Llwyn Uchel 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 immediate north, the A485 road to its west and the B4337 road to its east, and has the town of Llanybydder towards the north. 

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

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the accompanying Hills to be surveyed sub list with a 381m summit height, based on the twin 381m spot heights that appear on the Ordnance Survey 1:25,000 Explorer map, with an accompanying note stating; Two tops of same height (SN517388 is 383m on 1985 1:50000 map). 

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

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

LIDAR summit image of Pen Llwyn Uchel (SN 517 387)

The summit height produced by LIDAR analysis is 383.45m and is positioned at SN 51750 38783 and SN 51757 38784, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 383.45m and this was derived from LIDAR analysis, this is 2.45m higher than the previously listed summit height of 381m, which was based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Mynydd Pencarreg 

Name:  Pen Llwyn Uchel 

OS 1:50,000 map:  146

Summit Height (New Height):  383.45m (LIDAR)                                                           

Summit Grid Reference:  SN 51750 38783 & SN 51757 38784 (LIDAR) 

Bwlch Height:  359.6m (LIDAR) 

Bwlch Grid Reference:  SN 52370 38728 (LIDAR) 

Drop:  23.8m (LIDAR) 

 

Myrddyn Phillips (September 2023)

 

Mapping Mountains - Significant Height Revisions - Y Trichant

Pt. 315m (SN 673 337) - 51st significant height revision

Significant Name Changes post for Pt. 315m

 

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

The criteria for the list that this height revision applies to are:

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

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

The hill is being listed by the point (Pt. 315m) 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 Mynydd Mallaen group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned encircled by minor roads, with the B4302 road farther to its west, the A40 road farther to its south-east and the A482 road farther to its east, and has the village of Llanwrda towards the south-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a summit height of c 310m, based on the uppermost contour ring that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 313m summit height, based on interpolation of its uppermost 310m ring contour that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

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

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. 

Extract from the interactive mapping hosted on the Magic Maps website

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 315m summit spot height, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 315m and this was derived from the interactive map hosted on the Magic Maps website, this is 2m higher than the previously listed summit height of c 313m which was based on interpolation of its uppermost 310m contour ring that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Mynydd Mallaen 

Name:  Pt. 315m 

OS 1:50,000 map:  146

Summit Height (New Height):  315m (spot height)                                                           

Summit Grid Reference:  SN 67309 33794 (hand-held GPS via DoBIH) 

Bwlch Height:  c 271m (interpolation) 

Bwlch Grid Reference:  SN 66792 34530 (interpolation) 

Drop:  c 44m (spot height summit and interpolated bwlch) 

 

Myrddyn Phillips (June 2023)

Mapping Mountains - Significant Height Revisions - Y Trichant

Cefn Isaf (SN 800 486) - 50th significant height revision

Summit Relocations post for Cefn Isaf

 

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

LIDAR image of Cefn Isaf (SN 800 486)

The criteria for the list that this height revision applies to are:

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

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

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

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

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

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

LIDAR summit image of Cefn Isaf (SN 800 486)

LIDAR analysis gives the summit height of this hill as 386.0m and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 386.0m and this was derived from LIDAR analysis, this is 2.0m lower than the previously listed summit height of 388m which appears as a spot height on the Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Drygarn Fawr 

Name:  Cefn Isaf 

OS 1:50,000 map:  147

Summit Height (New Height):  386.0m (LIDAR)                                                           

Summit Grid Reference:  SN 80031 48623 (LIDAR) 

Bwlch Height:  345.5m (LIDAR) 

Bwlch Grid Reference:  SN 80361 48591 (LIDAR) 

Drop:  40.5m (LIDAR) 

 

Myrddyn Phillips (February 2023)

 

Mapping Mountains - Significant Height Revisions - Y Trichant

Banc Hafodau (SN 703 802) - 49th significant height revision

 

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

LIDAR image of Banc Hafodau (SN 703 802)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Banc Hafodau, and it is adjoined to the Banc Llechwedd Mawr group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B1), and it is positioned with the A44 road to its north and a minor road to its south, and has the village of Ponterwyd towards the east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a summit height of 346m, based on the spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

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

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 Hafodau (SN 703 802)

LIDAR analysis gives the summit height of this hill as 343.4m and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 343.4m and this was derived from LIDAR analysis, this is 2.6m lower than the previously listed summit height of 346m which appears as a spot height on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Banc Llechwedd Mawr 

Name:  Banc Hafodau 

OS 1:50,000 map:  135

Summit Height (New Height):  343.4m (LIDAR)                                                           

Summit Grid Reference:  SN 70334 80277 (LIDAR) 

Bwlch Height:  303.1m (LIDAR) 

Bwlch Grid Reference:  SN 71465 80258 (LIDAR) 

Drop:  40.3m (LIDAR) 

 

Myrddyn Phillips (January 2023)

Mapping Mountains - Significant Height Revisions - Y Trichant

Celynnog Hill (SO 051 971) - 48th significant height revision

 

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

LIDAR image of Celynnog Hill (SO 051 971)

The criteria for the list that this height revision applies to are:

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

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

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

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a summit height of 369m, based on the spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

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

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 Celynnog Hill (SO 051 971)

LIDAR analysis gives the summit height of this hill as 370.4m and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 370.4m and this was derived from LIDAR analysis, this is 1.4m higher than the previously listed summit height of 369m which appears as a spot height on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Carnedd Wen 

Name:  Celynnog Hill 

OS 1:50,000 map:  136

Summit Height (New Height):  370.4m (LIDAR)                                                           

Summit Grid Reference:  SO 05129 97189 (LIDAR) 

Bwlch Height:  330.4m (LIDAR) 

Bwlch Grid Reference:  SO 04838 97119 (LIDAR) 

Drop:  40.1m (LIDAR) 

 

Myrddyn Phillips (October 2022)

 

Mapping Mountains - Significant Height Revisions - Y Trichant

Cefn Llwyni (SJ 118 188) - 47th significant height revision

 

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

LIDAR image of Cefn Llwyni (SJ 118 188)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Cefn Llwyni, and it is adjoined to the Foel Cedig group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned with the B4393 road to its north-west and a minor road to its south-east, and has the town of Llanfyllin towards the east north-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a summit height of c 310m, with this being the uppermost ring contour on the contemporary Ordnance Survey 1:25,000 Explorer map. 

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 312m summit spot height and a 269m bwlch spot height, with these values giving this hill 43m 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 Llwyni (SJ 118 188)

LIDAR analysis gives the summit height of this hill as 308.3m and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 308.3m and this was derived from LIDAR analysis, this is 3.7m lower than the previously listed summit height of 312m which was derived from the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

 

The full details for the hill are: 

Group:  Foel Cedig 

Name:  Cefn Llwyni 

OS 1:50,000 map:  125

Summit Height (New Height):  308.3m (LIDAR)                                                           

Summit Grid Reference:  SJ 11845 18833 (LIDAR) 

Bwlch Height:  269.5m (LIDAR) 

Bwlch Grid Reference:  SJ 11850 18577 (LIDAR) 

Drop:  38.8m (LIDAR) 

 

Myrddyn Phillips (August 2022)

Mapping Mountains - Significant Height Revisions - Y Trichant

Boncyn Bwlch Glas (SJ 031 176) - 46th significant height revision

 

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

LIDAR image of Boncyn Bwlch Glas (SJ 031 176)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Boncyn Bwlch Glas, and it is adjoined to the Foel Cedig group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned with a minor road to its north, west and south, the B4395 road to its south-east and the B4393 road to its north-east, and has the village of Llanwddyn towards the north-west.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list with a summit height of c 320m with an accompanying note stating; Two points of same height.

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 321m summit height, based on interpolation of the uppermost 320m ring contour 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 gives the summit height of this hill as 323.5m and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 323.5m and this was derived from LIDAR analysis, this is 2.5m higher than the previously listed summit height of c 321m which was derived from interpolation of the uppermost 320m ring contour that appears on the Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Foel Cedig 

Name:  Boncyn Bwlch Glas 

OS 1:50,000 map:  125

Summit Height (New Height):  323.5m (LIDAR)                                                           

Summit Grid Reference:  SJ 03107 17613 (LIDAR) 

Bwlch Height:  293.8m (LIDAR) 

Bwlch Grid Reference:  SJ 03272 17643 (LIDAR) 

Drop:  29.7m (LIDAR) 

 

Myrddyn Phillips (July 2022)

 

 

Mapping Mountains - Significant Height Revisions - Y Trichant

Ffridd (SJ 038 121) - 45th significant height revision

Survey post for Ffridd

 

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

Ffridd (SJ 038 121)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Ffridd, and it is adjoined to the Esgeiriau Gwynion group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned with the B4395 road to its north-west, the A458 road to its south and the B4382 road to its east, and has the village of Llangadfan towards the west south-west.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a summit height of 329m, based on the spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

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

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 330m summit spot height.

One of the mapping resources now available online is the WalkLakes website which hosts an interactive map originated from the Ordnance Survey Open Data programme.  This map has many spot heights not on other publicly available maps and for this hill it has a small uppermost 330m contour.

Extract from the WalkLakes website

This hill has now been surveyed with the Trimble GeoXH 6000, resulting in a 330.6m summit height and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis. 

The Trimble GeoXH 6000 gathering data at the summit of Ffridd

Therefore, the new listed summit height of this hill is 330.6m and this was derived from a Trimble GeoXH 6000 survey, this is 1.6m higher than the previously listed summit height of 329m, which was based on the spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Esgeiriau Gwynion 

Name:  Ffridd 

OS 1:50,000 map:  125

Summit Height (New Height):  330.6m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SJ 03897 12140 (Trimble GeoXH 6000) 

Bwlch Height:  c 253m (interpolation) 

Bwlch Grid Reference:  SJ 03041 12323 (interpolation) 

Drop:  c 78m (Trimble GeoXH 6000 summit and interpolated bwlch)

Myrddyn Phillips (June 2022)

Mapping Mountains - Significant Height Revisions - Y Trichant

Bryniau Gwenllian (SJ 001 139) - 44th significant height revision

Hill Reclassifications post for Bryniau Gwenllian

Significant Name Changes post for Bryniau Gwenllian

 

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

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Bryniau Gwenllian and this was derived from the Tithe map, and it is adjoined to the Esgeiriau Gwynion group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned with a minor road to its south-west, the A458 road farther to its south-west and the B4395 road to its east, and has the village of Llangadfan towards the south south-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list, 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 20m of drop, based on an estimated c 355m summit height and an estimated c 335m 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

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. 

Extract from the Magic Maps website

One of the mapping resources now available online is 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 358m summit spot height and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 358m and this was derived from detail on contemporary maps produced from Ordnance Survey data, this is 3m higher than the previously listed summit height of c 355m, which was based on interpolation of 10m contouring that appear on the Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Esgeiriau Gwynion 

Name:  Bryniau Gwenllian 

OS 1:50,000 map:  125

Summit Height (New Height):  358m (spot height)                                                           

Summit Grid Reference:  SJ 00115 13999 (spot height) 

Bwlch Height:  c 336m (interpolation) 

Bwlch Grid Reference:  SJ 00435 14248 (interpolation) 

Drop:  c 22m (spot height summit and interpolated bwlch) 

 

Myrddyn Phillips (June 2022)

Mapping Mountains - Significant Height Revisions - Y Trichant

Waun Llwyd (SJ 003 165) - 43rd significant height revision

Hill Reclassifications post for Waun Llwyd

Significant Name Changes post for Waun Llwyd

 

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

LIDAR image of Waun Llwyd (SJ 003 165)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Waun Llwyd and this was derived from the Tithe map, and it is adjoined to the Esgeiriau Gwynion group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned with a minor road to its north and east, and has the village of Llanwddyn towards the north-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was 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 20m of drop, based on an estimated c 363m summit height and an estimated c 343m 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

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 Waun Llwyd (SJ 003 165)

LIDAR analysis gives the summit height of this hill as 367.4m and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 367.4m and this was derived from LIDAR analysis, this is 4.4m higher than the previously listed summit height of c 363m, which was based on interpolation of 10m contouring that appear on the Ordnance Survey 1:25,000 Explorer map.

 

The full details for the hill are: 

Group:  Esgeiriau Gwynion 

Name:  Waun Llwyd 

OS 1:50,000 map:  125

Summit Height (New Height):  367.4m (LIDAR)                                                           

Summit Grid Reference:  SJ 00323 16521 (LIDAR) 

Bwlch Height:  345.2m (LIDAR) 

Bwlch Grid Reference:  SJ 00193 16719 (LIDAR) 

Drop:  22.2m (LIDAR) 

 

Myrddyn Phillips (June 2022)

 

Mapping Mountains - Significant Height Revisions - Y Trichant

Lan Ddu Cilwenau (SN 572 371) - 42nd significant height revision

Summit Relocations post for Lan Ddu Cilwenau

Significant Name Changes post for Lan Ddu Cilwenau

 

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

LIDAR image of Lan Ddu Cilwenau (SN 572 371)

The criteria for the two listings that this height revision applies to are:

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

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

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

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

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

When the original Welsh 300m P30 list was published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a summit height of 328m, 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 summit image of Lan Ddu Cilwenau (SN 572 371)

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

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 333.1m and this was derived from LIDAR analysis, this is 5.1m higher than the previously listed summit height of 328m, which was based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map.

 

The full details for the hill are:

Group:  Mynydd Pencarreg 

Name:  Lan Ddu Cilwenau 

OS 1:50,000 map:  146

Summit Height (New Height):  333.1m (LIDAR) 

Summit Grid Reference:  SN 57277 37147 (LIDAR) 

Bwlch Height:  c 211m (interpolation) 

Bwlch Grid Reference:  SN 56467 37617 (interpolation) 

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

Dominance:  36.66% (LIDAR summit and interpolated bwlch) 

 

Myrddyn Phillips (May 2022)

 

Mapping Mountains - Significant Height Revisions - Y Trichant

Moel Fron Goch (SJ 008 208) - 41st significant height revision

Hill Reclassifications post for Moel Fron Goch

 

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

LIDAR image of Moel Fron Goch (SJ 008 208)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Moel Fron Goch, and it is adjoined to the Foel Cedig group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned with a minor road to its north-east, and the B4393 road and Llyn Efyrnwy (Lake Vyrnwy) to its south, and has the village of Llanwddyn towards the south-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was 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 22m of drop, based on the 333m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 311m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

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

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 Moel Fron Goch (SJ 008 208)

LIDAR analysis gives the summit height of this hill as 336.9m and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 336.9m and this was derived from LIDAR analysis, this is 3.9m higher than the previously listed summit height of 333m which appears as a spot height on the Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Foel Cedig 

Name:  Moel Fron Goch 

OS 1:50,000 map:  125

Summit Height (New Height):  336.9m (LIDAR)                                                           

Summit Grid Reference:  SJ 00828 20877 (LIDAR) 

Bwlch Height:  310.9m (LIDAR) 

Bwlch Grid Reference:  SJ 00834 21134 (LIDAR) 

Drop:  26.0m (LIDAR) 

 

Myrddyn Phillips (May 2022)

 

Mapping Mountains - Significant Height Revisions - Y Trichant

Moel y Belan (SJ 013 203) - 40th significant height revision

 

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

LIDAR image of Moel y Belan (SJ 013 203)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Moel y Belan, and it is adjoined to the Foel Cedig group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned with a minor road to its east and north, and the B4393 road and Llyn Efyrnwy (Lake Vyrnwy) to its south, and has the village of Llanwddyn towards the south-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was listed with a 359m summit height based on the spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

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

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 Moel y Belan (SJ 013 203)

LIDAR analysis gives the summit height of this hill as 345.6m and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

As the LIDAR result for this hill was so different to the Ordnance Survey spot height that appears on the 1:50,000 Landranger and 1:25,000 Explorer map, the Ordnance Survey series of Six-Inch maps were consulted, and the imperial height of 1134ft (345.6m) appears for this hill on this mapping.  It was also noted that a summit spot height of 345m appears on the interactive mapping available on the Magic Maps website. 

Extract from the Ordnance Survey series of Six-Inch maps

Therefore, the new listed summit height of this hill is 345.6m and this was derived from LIDAR analysis, this is 13.4m lower than the previously listed summit height of 359m which appears as a spot height on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Foel Cedig 

Name:  Moel y Belan 

OS 1:50,000 map:  125

Summit Height (New Height):  345.6m (LIDAR)                                                           

Summit Grid Reference:  SJ 01350 20335 (LIDAR) 

Bwlch Height:  309.45m (LIDAR) 

Bwlch Grid Reference:  SJ 01118 20667 (LIDAR) 

Drop:  36.2m (LIDAR) 

 

Myrddyn Phillips (May 2022)

Mapping Mountains - Significant Height Revisions - Y Trichant

Foel Fawr (SH 679 057) - 39th significant height revision

Summit Relocations post for Foel Fawr

 

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

LIDAR image of Foel Fawr (SH 679 057)

The criteria for the list that this height revision applies to are:

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

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

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

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

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

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

LIDAR summit image of Foel Fawr (SH 679 057)

LIDAR analysis gives the summit height of this hill as 343.9m and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are: 

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis. 

Therefore, the new listed summit height of this hill is 343.9m and this was derived from LIDAR analysis, this is 4.1m lower than the previously listed summit height of 348m which appears as a spot height on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Tarren y Gesail 

Name:  Foel Fawr 

OS 1:50,000 map:  124

Summit Height (New Height):  343.9m (LIDAR)                                                           

Summit Grid Reference:  SH 67982 05743 (LIDAR) 

Bwlch Height:  286.5m (LIDAR) 

Bwlch Grid Reference:  SH 67651 05532 (LIDAR) 

Drop:  57.4m (LIDAR) 

 

Myrddyn Phillips (March 2022)

Mapping Mountains - Significant Height Revisions - Y Trichant

Pared y Cefn Hir (SH 665 152) - 38th significant height revision

Hill Reclassifications post for Pared y Cefn Hir

 

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

Pared y Cefn Hir (SH 665 152)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Pared y Cefn Hir, and it is adjoined to the Cadair Idris group of hills, which are situated in the south-western part of North Wales (Region A, Sub-Region A3), and it is positioned with the A493 road to its north-west and minor roads to its south-west, south-east and east, and has the town of Abermaw (Barmouth) towards the west north-west. 

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list.  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 374m summit height based on interpolation of the uppermost 370m contour 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 image of Pared y Cefn Hir (SH 665 152)

LIDAR analysis gives the summit height of this hill as 379.0m and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are: 

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis. 

Therefore, the new listed summit height of this hill is 379.0m and this was derived from LIDAR analysis, this is 5.0m higher than the previously listed summit height of c 374m which was estimated from interpolation of the uppermost 370m contour that appears on the contemporary Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Cadair Idris 

Name:  Pared y Cefn Hir 

OS 1:50,000 map:  124

Summit Height (New Height):  379.0m (LIDAR)                                                           

Summit Grid Reference:  SH 66579 15214 (LIDAR) 

Bwlch Height:  358.4m (LIDAR) 

Bwlch Grid Reference:  SH 66538 15146 (LIDAR) 

Drop:  20.5m (LIDAR) 

 

Myrddyn Phillips (March 2022)

 

 

Mapping Mountains - Significant Height Revisions - Y Trichant

Moel Gwyn Fynydd (SH 736 288) - 37th significant height revision

 

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

LIDAR image of Moel Gwyn Fynydd (SH 736 288)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Moel Gwyn Fynydd, and it is adjoined to the Arenig group of hills, which are situated in the central part of North Wales (Region A, Sub-Region A3), and it is positioned with a minor road to its west and south, and the A470 road farther to its west, and has the village of Trawsfynydd towards the north north-west. 

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was listed with a 385m summit height based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map, with an accompanying note stating; 386m on 1984 1:50,000 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 gives the summit height of this hill as 387.1m and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are: 

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis. 

Therefore, the new listed summit height of this hill is 387.1m and this was derived from LIDAR analysis, this is 2.1m higher than the originally listed summit height of 385m which appears as a spot height on the contemporary Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Arenig 

Name:  Moel Gwyn Fynydd 

OS 1:50,000 map:  124

Summit Height (New Height):  387.1m (LIDAR)                                                           

Summit Grid Reference:  SH 73674 28884 (LIDAR) 

Bwlch Height:  336.5m (LIDAR) 

Bwlch Grid Reference:  SH 74542 29998 (LIDAR) 

Drop:  50.6m (LIDAR) 

 

Myrddyn Phillips (December 2021)

 

Mapping Mountains - Significant Height Revisions - Y Trichant

Moel Hafod yr Ŵyn (SH 842 322) - 36th significant height revision

 

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

LIDAR image of Moel Hafod yr Ŵyn (SH 842 322)

The criteria for the list that this height revision applies to are:

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

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

The name the hill is listed by is Moel Hafod yr Ŵyn, and it is adjoined to the Arenig group of hills, which are situated in the central part of North Wales (Region A, Sub-Region A3), and it is positioned with a minor road to its south-west and east, and has the village of Llanuwchllyn towards the south-east. 

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was listed with a 389m summit height based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map, with the caveat that the uppermost 390m ring contour had been missed. 

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-evaluated and it was listed with 37m of drop, based on the 396m summit spot height that appears on the Harvey 1:40,000 Snowdonia South British Mountain Map and the 359m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

Extract from the Harvey 1:40,000 Snowdonia South British Mountain 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 summit height of this hill as 398.1m and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are: 

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height, has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis. 

Therefore, the new listed summit height of this hill is 398.1m and this was derived from LIDAR analysis, this is 9.1m higher than the originally listed summit height of 389m which appears as a spot height on the contemporary Ordnance Survey 1:25,000 Explorer map and 2.1m higher than the 396m summit spot height that appears on the Harvey 1:40,000 Snowdonia South British Mountain Map. 

 

The full details for the hill are: 

Group:  Arenig 

Name:  Moel Hafod yr Ŵyn 

OS 1:50,000 map:  124, 125

Summit Height (New Height):  398.1m (LIDAR)                                                           

Summit Grid Reference:  SH 84205 32245 (LIDAR) 

Bwlch Height:  358.2m (LIDAR) 

Bwlch Grid Reference:  SH 84034 32465 (LIDAR) 

Drop:  39.8m (LIDAR) 

 

Myrddyn Phillips (December 2021)