Mapping Mountains - Hill Reclassifications - 200m Twmpau

 

200m Twmpau – Hill Reclassifications

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

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

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Cefn Coch (SN 747 962) – Sub-Trichant reclassified to 200m Sub-Twmpau (70th reclassification)

There has been a reclassification to the list of Y Trichant – The 300m Hills of Wales and the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived by LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cefn Coch (SN 747 962)

The criteria for the two listings that this reclassification 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

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Cefn Coch, 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 A487 road to its west and a minor roads to its east, and has the town of Machynlleth towards the north.

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list with an estimated summit height of c 300m based on interpolation of the uppermost ring contour that appears on the Ordnance Survey 1:25,000 Explorer map, with an accompanying note stating; Three points of same height, indicating three separate 300m ring contours. 

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.

Therefore, the reclassification of this hill is due to LIDAR analysis, resulting in 24.6m of drop, with a 299.7m summit height and a 275.1m bwlch height.  Therefore, as the summit height is insufficient for Sub-Trichant status the hill is reclassified to a 200m Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Banc Llechwedd Mawr 

Name:  Cefn Coch 

OS 1:50,000 map:  135

Summit Height:  299.7m (LIDAR)                                                           

Summit Grid Reference:  SN 74725 96284 (LIDAR) 

Bwlch Height:  275.1m (LIDAR) 

Bwlch Grid Reference:  SN 75003 95681 (LIDAR) 

Drop:  24.6m (LIDAR) 

 

Myrddyn Phillips (December 2022)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Banc Pontfaen (SN 564 484) – 200m Sub-Twmpau reclassified to 200m Twmpau (69th reclassification)

Summit Relocations post for Banc Pontfaen

Significant Name Changes post for Banc Pontfaen

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Banc Pontfaen (SN 564 484)

The criteria for the list that this reclassification applies to are:

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

The 200m Twmpau by Myrddyn Phillips

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

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

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

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and its summit relocated to SN 564 484 and listed with an estimated c 32m of drop, based on an estimated c 226m summit height and an estimated c 194m bwlch height, with both heights based on interpolation of 5m contouring that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.

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

Therefore, the confirmation of the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 225.6m summit height and a 194.2m bwlch height, with these values giving this hill 31.4m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Mynydd Bach 

Name:  Banc Pontfaen 

OS 1:50,000 map:  146

Summit Height:  225.6m (LIDAR) 

Summit Grid Reference:  SN 56441 48477 (LIDAR) 

Bwlch Height:  194.2m (LIDAR) 

Bwlch Grid Reference:  SN 55294 49452 (LIDAR) 

Drop:  31.4m (LIDAR) 

 

Myrddyn Phillips (December 2022)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Cae Pen Crug (SN 654 592) – 200m Sub-Twmpau reclassified to 200m Twmpau (68th reclassification)

Summit Relocations post for Cae Pen Crug

Significant Height Revisions post for Cae Pen Crug

Significant Name Changes post for Cae Pen Crug

There has been a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cae Pen Crug (SN 654 592)

The criteria for the list that this reclassification applies to are:

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

The 200m Twmpau by Myrddyn Phillips

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

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was 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.

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 28m of drop, based on the 224m spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 196m bwlch height, based on interpolation of 10m contouring between 190m – 200m. 

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.

Therefore, the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 229.1m summit height and a 194.2m bwlch height, with these values giving this hill 34.9m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Mynydd Bach 

Name:  Cae Pen Crug 

OS 1:50,000 map:  146

Summit Height:  229.1m (LIDAR) 

Summit Grid Reference:  SN 65493 59251 (LIDAR) 

Bwlch Height:  194.2m (LIDAR) 

Bwlch Grid Reference:  SN 65231 59601 (LIDAR) 

Drop:  34.9m (LIDAR) 

 

Myrddyn Phillips (October 2022)

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Moel y Crio (SJ 199 696) – 200m Sub-Twmpau addition (67th reclassification)

Survey post for Moel y Crio

Significant Height Revisions post for Moel y Crio

Summit Relocations post for Moel y Crio

There has been an addition to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from a Trimble GeoXH 6000 survey conducted by Myrddyn Phillips with assistance from Mark Trengove. 

Moel y Crio (SJ 199 696)

The criteria for the list that this addition applies to are:

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Moel y Crio, and it is adjoined to the Moel y Gamelin group of hills, which are situated in the north-eastern part of North Wales (Region A, Sub-Region A2), and it is positioned encircled by minor roads with the B5123 road farther to its east, and has the town of Yr Wyddgrug (Mold) towards the south-east.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category. 

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 14m of drop, based on the 292m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 278m bwlch height, based on interpolation of 5m contouring between 275m – 280m that appear on the Ordnance Survey 1:25,000 Explorer map.  This hill has now been accurately surveyed with the Trimble GeoXH 6000, resulting in its addition as a 200m Sub-Twmpau. 

The Trimble GeoXH 6000 gathering data at the summit of Moel y Crio

The Trimble GeoXH 6000 gathering data at the bwlch of Moel y Crio

Therefore, the addition of this hill to 200m Sub-Twmpau status is due to a Trimble GeoXH 6000 survey, resulting in a 297.5m summit height and a 276.8m bwlch height, with these values giving this hill 20.7m of drop, which is sufficient for it to be classified as a 200m Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Moel y Gamelin 

Name:  Moel y Crio 

OS 1:50,000 map:  116

Summit Height:  297.5m (converted to OSGM15) 

Summit Grid Reference:  SJ 19988 69614 

Bwlch Height:  276.8m (converted to OSGM15) 

Bwlch Grid Reference:  SJ 20406 69385 

Drop:  20.7m 

 

Myrddyn Phillips (August 2022)

 

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Copa’r Frân (SJ 206 703) – 200m Sub-Twmpau addition (66th reclassification)

Survey post for Copa’r Frân

Significant Name Changes post for Copa’r Frân

There has been confirmation of an addition to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from a Leica GS15 bwlch survey conducted by John Barnard and Graham Jackson and a Trimble GeoXH 6000 summit survey conducted by Myrddyn Phillips with assistance from Mark Trengove. 

Copa'r Frân (SJ 206 703)

The criteria for the list that this addition applies to are:

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Copa’r Frân and this was derived from local enquiry, and it is adjoined to the Moel y Gamelin group of hills, which are situated in the north-eastern part of North Wales (Region A, Sub-Region A2), and it is positioned with a minor road to its south-west and the B5123 road to its east, and has the town of Yr Wyddgrug (Mold) towards the south south-east.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was 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 22m of drop, based on an estimated c 285m summit height and an estimated c 263m bwlch height, with both heights based on interpolation of 5m contouring that appear on the Ordnance Survey 1:25,000 Explorer map. 

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

This hill has now been accurately surveyed with its bwlch using the Leica GS15 and its summit with the Trimble GeoXH 6000, resulting in its confirmation as a 200m Sub-Twmpau. 

The Trimble GeoXH 6000 gathering data at the summit of Copa'r Frân

Therefore, the confirmation of the addition of this hill to 200m Sub-Twmpau status is due to a Leica GS15 bwlch survey and a Trimble GeoXH 6000 summit survey, resulting in a 286.1m summit height and a 265.7m bwlch height, with these values giving this hill 20.4m of drop, which is sufficient for it to be classified as a 200m Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Moel y Gamelin 

Name:  Copa’r Frân 

OS 1:50,000 map:  117

Summit Height:  286.1m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SJ 20624 70354 (Trimble GeoXH 6000) 

Bwlch Height:  265.7m (converted to OSGM15, Leica GS15) 

Bwlch Grid Reference:  SJ 20803 70065 (Leica GS15) 

Drop:  20.4m (Trimble GeoXH 6000 summit and Leica GS15 bwlch) 

 

Myrddyn Phillips (August 2022)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Glantrenfach (SN 524 426) – 200m Sub-Twmpau reclassified to 200m Twmpau (65th reclassification)

Significant Name Changes post for Glantrenfach

There has been a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Glantrenfach (SN 524 426)

The criteria for the list that this reclassification applies to are:

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Glantrenfach and this was derived from the Tithe map, and it is adjoined to the Mynydd Pencarreg group of hills, which are situated in the south-western part of South Wales (Region B, Sub-Region B1), and it is positioned with a minor road to its immediate west, the A485 road to its north-west and the B4337 road to its north-east, and has the town of Llanybydder towards the north.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was 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.

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 28m of drop, based on the 201m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 173m bwlch height, based on interpolation of 10m contouring between 170m – 180m. 

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 5m contouring, enabling the interpolated bwlch height to be better judged, resulting it this being amended to c 172m, with this value giving this hill an estimated c 29m 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.

Therefore, the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 201.5m summit height and a 170.4m bwlch height, with these values giving this hill 31.1m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Mynydd Pencarreg 

Name:  Glantrenfach 

OS 1:50,000 map:  146

Summit Height:  201.5m (LIDAR) 

Summit Grid Reference:  SN 52425 42608 (LIDAR) 

Bwlch Height:  170.4m (LIDAR) 

Bwlch Grid Reference:  SN 52798 42397 (LIDAR) 

Drop:  31.1m (LIDAR) 

 

Myrddyn Phillips (July 2022)

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Parc Pal (SN 354 246) – 200m Twmpau reclassified to 200m Sub-Twmpau (64th reclassification)

Significant Name Changes post for Parc Pal

There has been a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Parc Pal (SN 354 246)

The criteria for the list that this reclassification applies to are:

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Parc Pal and this was derived from the Tithe map, and it is adjoined to the Mynydd Pencarreg group of hills, which are situated in the south-western part of South Wales (Region B, Sub-Region B1), and it is positioned encircled by minor roads, with the A484 road farther to its north-east, the B4299 road farther to its west and the B4298 and A40 roads father to its south, and has the town of Caerfyrddin (Carmarthen) towards the south-east.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was 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.

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 29m of drop, based on the 227m summit spot height adjoined to a triangulation pillar that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 198m bwlch height, based on interpolation of 5m contouring between 195m – 200m. 

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 228m summit spot height and when coupled with the estimated c 198m bwlch height, these values gave this hill an estimated c 30m 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.

Therefore, the reclassification of this hill to 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 227.2m summit height and a 198.6m bwlch height, with these values giving this hill 28.6m of drop, which is insufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Mynydd Pencarreg 

Name:  Parc Pal 

OS 1:50,000 map:  145, 159

Summit Height:  227.2m (LIDAR) 

Summit Grid Reference:  SN 35443 24619 & SN 35456 24637 & SN 35458 24640 (LIDAR) 

Bwlch Height:  198.6m (LIDAR) 

Bwlch Grid Reference:  SN 37285 25364 (LIDAR) 

Drop:  28.6m (LIDAR) 

 

Myrddyn Phillips (June 2022)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Wern Ddu (SN 734 366) – 200m Sub-Twmpau reclassified to 200m Twmpau (63rd reclassification)

Significant Name Changes post for Wern Ddu

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Wern Ddu (SN 734 366)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Wern Ddu and this was derived from the Tithe map, and it is adjoined to the Mynydd Mallaen group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned encircled by minor roads, with the A482 road farther to its west and the A40 road farther to its south-east, and has the town of Llanymddyfri (Llandovery) towards the south-east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 33m of drop, based on the 208m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 175m bwlch height, based on interpolation of 10m contouring between 170m – 180m. 

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. 

Therefore, the confirmation of the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 207.9m summit height and a 171.5m bwlch height, with these values giving this hill 36.4m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Mynydd Mallaen 

Name:  Wern Ddu 

OS 1:50,000 map:  146, 160

Summit Height:  207.9m (LIDAR) 

Summit Grid Reference:  SN 73474 36636 (LIDAR) 

Bwlch Height:  171.5m (LIDAR) 

Bwlch Grid Reference:  SN 73922 36372 (LIDAR) 

Drop:  36.4m (LIDAR) 

 

Myrddyn Phillips (March 2022)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Rhandir Llwyn Piod (SN 593 281) – 200m Sub-Twmpau reclassified to 200m Twmpau (62nd reclassification)

Significant Name Changes post for Rhandir Llwyn Piod

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data. 

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Rhandir Llwyn Piod and this was derived from the Tithe map, and it is adjoined to the Mynydd Mallaen group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned encircled by minor roads, with the A40 road farther to its south, and has the town of Llandeilo towards the south south-east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 31m of drop, based on the 257m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 226m bwlch height, based on interpolation of 10m contouring between 220m – 230m. 

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. 

One of the resources recently available online is the mapping on the OS Maps website and the details for this hill were subsequently re-assessed against this mapping.  This is the replacement for OS Get-a-map and until recent times had contours at 5m intervals which were proving consistently more accurate compared to the 5m contours that sometimes appear on the Ordnance Survey 1:25,000 Explorer map and used to appear on the online Vector Map Local.  This mapping had bwlch contouring between 225m – 230m, with interpolation placing the height of the bwlch as an estimated c 227m, resulting in the drop value for this hill being amended to an estimated c 30m. 

Therefore, the reclassification of this hill from 200m Sub-Twmpau status is due to detail on contemporary maps produced from Ordnance Survey data, resulting in a 257m summit height and an estimated c 227m bwlch height, with these values giving this hill an estimated c 30m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Mynydd Mallaen 

Name:  Rhandir Llwyn Piod 

OS 1:50,000 map:  146

Summit Height:  257m (spot height) 

Summit Grid Reference:  SN 59308 28166 (hand-held GPS via DoBIH) 

Bwlch Height:  c 227m (interpolation) 

Bwlch Grid Reference:  SN 60257 29082 (interpolation) 

Drop:  c 30m (spot height summit and interpolated bwlch) 

 

Myrddyn Phillips (March 2022)

 

 

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Ugain (SO 126 320 & SO 127 320) – 200m Sub-Twmpau reclassified to 200m Twmpau (61st reclassification)

Significant Name Changes post for Ugain

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Ugain (SO 126 320 & SO 127 320)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Ugain and this was derived from the Tithe map, and it is adjoined to the Mynydd Epynt group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned enclosed by minor roads, with the A470 road farther to its north-west and the B4560 road and A479 road farther to its east, and has the town of Talgarth towards the north-east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 29m of drop, based on the 243m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 214m bwlch height, based on interpolation of 10m contouring between 210m – 220m. 

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 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 213m bwlch spot height, which when coupled with the 243m summit spot height gave this hill 30m 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. 

Therefore, the confirmation of the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 243.0m summit height and a 212.1m bwlch height, with these values giving this hill 30.8m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Mynydd Epynt 

Name:  Ugain 

OS 1:50,000 map:  161

Summit Height:  243.0m (LIDAR) 

Summit Grid Reference:  SO 12694 32007 & SO 12698 32008 & SO 12700 32007 & SO 12699 32004 (LIDAR) 

Bwlch Height:  212.1m (LIDAR) 

Bwlch Grid Reference:  SO 12214 32682 (LIDAR) 

Drop:  30.8m (LIDAR)

 

Myrddyn Phillips (March 2022)

 

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Cae o Flaen y Drws (SN 994 540) – 200m Sub-Twmpau reclassified to 200m Twmpau (60th reclassification)

Significant Name Changes post for Cae o Flaen y Drws

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cae o Flaen y Drws (SN 994 540)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Cae o Flaen y Drws and this was derived from the Tithe map, and it is adjoined to the Drygarn Fawr group of hills, which are situated in the central part of the South Wales Region (Region B, Sub-Region B1), and it is positioned with minor roads to its north-east and south-west, the B4358 road to its north-west, the A483 road to its south and the A470 road to its east, and has the town of Llanfair-ym-Muallt (Builth Wells) towards the south-east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 31m of drop, based on the 214m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 183m bwlch height, based on interpolation of 10m contouring between 180m – 190m. 

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. 

Therefore, the confirmation of the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 213.1m summit height and a 180.7m bwlch height, with these values giving this hill 32.4m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Drygarn Fawr 

Name:  Cae o Flaen y Drws 

OS 1:50,000 map:  147

Summit Height:  213.1m (LIDAR) 

Summit Grid Reference:  SN 99449 54001 (LIDAR) 

Bwlch Height:  180.7m (LIDAR) 

Bwlch Grid Reference:  SN 98753 54175 (LIDAR) 

Drop:  32.4m (LIDAR) 

 

Myrddyn Phillips (January 2022) 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Allt Mes (SN 795 397) – 200m Sub-Twmpau reclassified to 200m Twmpau (59th reclassification) 

Significant Height Revisions post for Allt Mes

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Allt Mes (SN 795 397)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Allt Mes, and it is adjoined to the Drygarn Fawr group of hills, which are situated in the central part of the South Wales Region (Region B, Sub-Region B1), and it is positioned with minor roads to its north-east, north-west and south-west, and the A483 road to its south-east, and has the town of Llanymddyfri (Llandovery) towards the south south-west. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 33m of drop, based on the 217m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 184m bwlch height, based on interpolation of 10m contouring between 180m – 190m 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. 

Therefore, the confirmation of the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 219.4m summit height and a 182.8m bwlch height, with these values giving this hill 36.6m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Drygarn Fawr 

Name:  Allt Mes 

OS 1:50,000 map:  146, 160

Summit Height:  219.4m (LIDAR) 

Summit Grid Reference:  SN 79575 39715 (LIDAR) 

Bwlch Height:  182.8m (LIDAR) 

Bwlch Grid Reference:  SN 79199 39937 (LIDAR) 

Drop:  36.6m (LIDAR) 

 

Myrddyn Phillips (January 2022)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Pt. 245.2m (SN 917 502) – 200m Sub-Twmpau reclassified to 200m Twmpau (58th reclassification)

Significant Name Changes post for Pt. 245.2m

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Pt. 245.2m (SN 917 502)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The hill is being listed by the point (Pt. 245.2m) notation as an appropriate name for it either through local enquiry and/or historic research has not been found by the author, and it is adjoined to the Drygarn Fawr group of hills, which are situated in the central part of the South Wales Region (Region B, Sub-Region B1), and it is positioned with the A483 road to its north-west, and minor roads to its south and east, and has the village of Beulah towards the north. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 33m of drop, based on the 245m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 212m bwlch height based on interpolation of 10m contouring between 210m – 220m 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. 

Therefore, the confirmation of the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 245.2m summit height and a 213.0m bwlch height, with these values giving this hill 32.2m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Drygarn Fawr 

Name:  Pt. 245.2m 

OS 1:50,000 map:  147

Summit Height:  245.2m (LIDAR) 

Summit Grid Reference:  SN 91735 50259 (LIDAR) 

Bwlch Height:  213.0m (LIDAR) 

Bwlch Grid Reference:  SN 91241 50744 (LIDAR) 

Drop:  32.2m (LIDAR) 

 

Myrddyn Phillips (January 2022)

 

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Comin y Garth (SN 982 548) – 200m Twmpau reclassified to 200m Sub-Twmpau (57th reclassification)

There has been a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Comin y Garth (SN 982 548)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Comin y Garth and it is adjoined to the Drygarn Fawr group of hills, which are situated in the central part of the South Wales Region (Region B, Sub-Region B1), and it is positioned with the B4358 road to its north-west, minor roads to its south-west and north-east and the A470 road farther to its east, and has the village of Newbridge-on-Wye towards the north-east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 32m of drop, based on the 248m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 216m bwlch height, based on interpolation of 10m contouring between 210m – 220m that also appear on the Ordnance Survey 1:25,000 Explorer map. 

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

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and for this hill it had a 218m spot height on the area of the bwlch, and when coupled with the 248m summit spot height these values gave this hill 30m of drop.  The 218m bwlch spot height also appears on the interactive mapping available on the Magic Maps website. 

Extract from the Magic Maps website

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

Therefore, the reclassification of this hill to 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 246.9m summit height and a 217.5m bwlch height, with these values giving this hill 29.5m of drop, which is insufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Drygarn Fawr 

Name:  Comin y Garth 

OS 1:50,000 map:  147

Summit Height:  246.9m (LIDAR) 

Summit Grid Reference:  SN 98265 54889 (LIDAR) 

Bwlch Height:  217.5m (LIDAR) 

Bwlch Grid Reference:  SN 98505 55433 (LIDAR) 

Drop:  29.5m (LIDAR) 

 

Myrddyn Phillips (January 2022)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Cefn Bwlch Cennant (SN 802 424) – 200m Sub-Twmpau reclassified to 200m Twmpau (56th reclassification)

Summit Relocations post for Cefn Bwlch Cennant

Significant Name Changes post for Cefn Bwlch Cennant

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cefn Bwlch Cennant (SN 802 424)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

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

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 29m of drop, based on an estimated c 283m summit height and an estimated c 254m bwlch height, with both heights based on interpolation of 10m contouring that appear on the Ordnance Survey 1:25,000 Explorer map. 

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

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and for this hill it had a 282m summit spot height and a 251m bwlch spot height, with these values giving this hill 31m of drop. 

Another of the mapping resources now available online is the Magic Maps website which hosts an interactive map originated from Ordnance Survey data.  This mapping also shows a 282m spot height on the summit area of this hill. 

Extract from the Magic Maps website

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

Therefore, the confirmation of the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 281.2m summit height and a 250.55m bwlch height, with these values giving this hill 30.6m of drop, which is sufficient for it to be classified as a 200m Twmpau.  With the caveat that LIDAR gives a 281.6m height to a raised boundary bank that is considered a relatively recent man-made construct and therefore is not taken as a part of the height of this hill. 

 

The full details for the hill are: 

Group:  Drygarn Fawr 

Name:  Cefn Bwlch Cennant 

OS 1:50,000 map:  147, 160

Summit Height:  281.2m (LIDAR) 

Summit Grid Reference:  SN 80249 42439 (LIDAR) 

Bwlch Height:  250.55m (LIDAR) 

Bwlch Grid Reference:  SN 80310 42683 (LIDAR) 

Drop:  30.6m (LIDAR) 

 

Myrddyn Phillips (January 2022)

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Lan (SN 972 529) – 200m Sub-Twmpau reclassified to 200m Twmpau (55th reclassification)

Significant Name Changes post for Lan

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Lan (SN 972 529)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Lan and this was derived from the Tithe map, and it is adjoined to the Drygarn Fawr group of hills, which are situated in the central part of the South Wales Region (Region B, Sub-Region B1), and it is positioned encircled by minor roads, with the B4358 road farther to its north-west and the A483 road farther to its south, and has the town of Llanfair-ym-Muallt (Builth Wells) towards the east south-east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 27m of drop, based on an estimated c 284m summit height and an estimated c 257m bwlch height, with both heights based on interpolation of 10m contouring that appear on the Ordnance Survey 1:25,000 Explorer map. 

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

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and for this hill it had a 252m spot height on the area of the bwlch, and when coupled with a reassessment of the estimated summit height of this hill of c 285m, these values gave this hill an estimated c 33m 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. 

Therefore, the confirmation of the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 284.9m summit height and a 251.2m bwlch height, with these values giving this hill 33.7m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Elenydd 

Name:  Lan 

OS 1:50,000 map:  147

Summit Height:  284.9m (LIDAR) 

Summit Grid Reference:  SN 97265 52939 (LIDAR) 

Bwlch Height:  251.2m (LIDAR) 

Bwlch Grid Reference:  SN 97057 53035 (LIDAR) 

Drop:  33.7m (LIDAR) 

 

Myrddyn Phillips (January 2022)

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Pen Llys (SN 998 584) – 200m Sub-Twmpau reclassified to 200m Twmpau (54th reclassification)

Survey post for Pen Llys

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis and a subsequent Trimble GeoXH 6000 summit survey conducted by Myrddyn Phillips.

LIDAR image of Pen Llys (SN 998 584)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Pen Llys and it is adjoined to the Elenydd group of hills, which are situated in the central part of the Mid and West Wales Region (Region B, Sub-Region B2), and it is positioned with minor roads to its north-west, east and north-east, the B4358 road to its south-east and the A470 road farther to its north-east, and has the village of Newbridge-on-Wye towards the east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 30m of drop, based on the 292m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 262m bwlch height, based on interpolation of 10m contouring between 260m – 270m that appear on the Ordnance Survey 1:25,000 Explorer map. 

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

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and for this hill it had a 262m spot height on the area of the bwlch, and when coupled with the 292m summit spot height these values gave this hill 30m 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. 

The result produced by LIDAR analysis gives this hill a 291.5m summit height, and as the summit has now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes.

The Trimble GeoXH 6000 gathering data at the summit of Pen Llys

Therefore, the confirmation of the reclassification of this hill to 200m Twmpau status is due to LIDAR analysis and a subsequent Trimble GeoXH 6000 survey, resulting in a 291.8m summit height and a 261.3m bwlch height, with these values giving this hill 30.6m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

The full details for the hill are: 

Group:  Elenydd 

Name:  Pen Llys 

OS 1:50,000 map:  147

Summit Height:  291.8m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SN 99830 58439 (Trimble GeoXH 6000) 

Bwlch Height:  261.3m (LIDAR) 

Bwlch Grid Reference:  SN 99569 58593 (LIDAR) 

Drop:  30.6m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (December 2021)

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Coed Ffridd Fawr (SH 869 033) – 200m Sub-Twmpau reclassified to 200m Twmpau (53rd reclassification)

Summit Relocations post for Coed Ffridd Fawr

Significant Name Changes post for Coed Ffridd Fawr

There has been a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill initiated by Joe Nuttall who produced a summit analysis programme using LIDAR, and then by LIDAR analysis initially conducted by Jim Bloomer and subsequently by Myrddyn Phillips. 

LIDAR image of Coed Ffridd Fawr (SH 869 033)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Coed Ffridd Fawr and it is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is positioned with a minor road to its north and the A470 road to its south, and has the village of Llanbryn-mair towards the east south-east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 29m of drop, based on the 242m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 213m bwlch height, based on interpolation of 10m contouring between 210m – 220m. 

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

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and for this hill it had a 214m spot height on the area of the bwlch, and when coupled with the 242m summit spot height these values gave this hill 28m 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. 

Therefore, the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 244.0m summit height and a 213.5m bwlch height, with these values giving this hill 30.5m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Carnedd Wen 

Name:  Coed Ffridd Fawr 

OS 1:50,000 map:  135, 136

Summit Height:  244.0m (LIDAR) 

Summit Grid Reference:  SH 86944 03372 (LIDAR) 

Bwlch Height:  213.5m (LIDAR) 

Bwlch Grid Reference:  SH 87416 03786 (LIDAR) 

Drop:  30.5m (LIDAR) 

 

Myrddyn Phillips (October 2021)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Ffridd Eithaf (SN 745 977) – 200m Twmpau deletion (52nd reclassification)

Survey post for Ffridd Eithaf

There has been a deletion to the list of the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Ffridd Eithaf (SN 745 977)

The criteria for the list that this deletion applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Ffridd Eithaf and it is adjoined to the Pumlumon group of hills, which are situated in the north-western part of Mid and West Wales (Region B, Sub-Region B2), and it is positioned with the A489 road to its north north-east, minor roads to its west, south and east, and the A487 road farther to its north-west and has the town of Machynlleth towards the north. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a summit height of 272m.

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 35m of drop, based on the 272m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 237m bwlch height, based on interpolation of 10m contouring between 230m – 240m.  

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

When the listing that became known as The Welsh P15s was being compiled, the adjacent hill listed as Ffridd Cae Crydd (SN 749 976) was included in the accompanying P14 sub list with an estimated c 14m of drop, based on an estimated c 271m summit height and an estimated c 257m bwlch height, with both heights based on interpolation of 10m contouring that appear on the Ordnance Survey 1:25,000 Explorer map. 

LIDAR image of Ffridd Cae Crydd (SN 749 976) on right and Ffridd Eithaf (SN 745 977) on left

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

LIDAR image of Ffridd Eithaf (SN 745 977)

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

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

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

 

Ffridd Cae Crydd:  272.289m at SN 74910 97692 

Ffridd Eithaf:  272.175m at SN 74578 97750 

 

Therefore, the confirmation of the deletion of this hill from 200m Twmpau status is due to LIDAR analysis and a subsequent Trimble GeoXH 6000 survey, resulting in a 272.2m summit height and a 255.7m bwlch height, with these values giving this hill 16.5m of drop, which is sufficient for it to retain its Welsh P15 status. 

 

The full details for the hill are: 

Group:  Pumlumon 

Name:  Ffridd Eithaf 

OS 1:50,000 map:  135

Summit Height:  272.2m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SN 74578 97750 (Trimble GeoXH 6000) 

Bwlch Height:  255.7m (LIDAR) 

Bwlch Grid Reference:  SN 74763 97683 (LIDAR) 

Drop:  16.5m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (October 2021)

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Ffridd Cae Crydd (SN 749 976) – Welsh Sub-P15 reclassified to 200m Twmpau (51st reclassification)

Survey post for Ffridd Cae Crydd

Summit Relocations post for Ffridd Cae Crydd

There has been a reclassification to the list of The Welsh P15s and the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Ffridd Cae Crydd (SN 749 976)

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

The Welsh P15s – Welsh hills with 15m minimum drop, irrespective of their height, with an accompanying sub list entitled the Welsh Sub-P15s, with the criteria for this sub category being all Welsh hills with 14m or more and below 15m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list appearing on Mapping Mountains on the 10^th May 2019. 

The Welsh P15s by Myrddyn Phillips

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Ffridd Cae Crydd and it is adjoined to the Pumlumon group of hills, which are situated in the north-western part of Mid and West Wales (Region B, Sub-Region B2), and it is positioned with the A489 road to its north and minor roads to its west, south and east, and has the town of Machynlleth towards the north.

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

When the listing that became known as The Welsh P15s was being compiled, this hill was included in the P14 sub list with an estimated c 14m of drop, based on an estimated c 271m summit height and an estimated c 257m bwlch height, with both heights based on interpolation of 10m contouring that appear on the Ordnance Survey 1:25,000 Explorer map.  With an adjacent hill listed as Ffridd Eithaf (SN 745 977) given a summit height of 272m based on the spot height that appears on the contemporary Ordnance Survey 1:25,000 Explorer map. 

LIDAR image of Ffridd Cae Crydd (SN 749 976) on right and Ffridd Eithaf (SN 745 977) on left

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

The Trimble GeoXH 6000 gathering data at the summit of Ffridd Cae Crydd with the summit of Ffridd Eithaf in the background

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

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

 

Ffridd Cae Crydd:  272.289m at SN 74910 97692 

Ffridd Eithaf:  272.175m at SN 74578 97750 

 

Therefore, the confirmation of the reclassification of this hill from Welsh Sub-P15 status is due to LIDAR analysis and a subsequent Trimble GeoXH 6000 survey, resulting in a 272.3m summit height and a 232.8m bwlch height, with these values giving this hill 39.4m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Pumlumon 

Name:  Ffridd Cae Crydd 

OS 1:50,000 map:  135

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

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

Bwlch Height:  232.8m (LIDAR) 

Bwlch Grid Reference:  SN 75107 97628 (LIDAR) 

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

 

Myrddyn Phillips (October 2021)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Pen yr Allt (SH 842 025) – 200m Sub-Twmpau addition (50th reclassification)

Survey post for Pen yr Allt

There has been confirmation of an addition to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Pen yr Allt (SH 842 025)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Pen yr Allt and it is adjoined to the Pumlumon group of hills which are situated in the north-western part of Mid and West Wales (Region B, Sub-Region B2), and it is encircled by minor roads with the A470 road farther to its north-east, and has the village of Comins-coch towards the north-east. 

When the original 200m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category. 

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 25m of drop, based on the 267m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 242m bwlch height based on interpolation of 10m contouring between 240m – 250m. 

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

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

LIDAR summit image of Pen yr Allt (SH 842 025)

Currently LIDAR only covers the summit area of this hill and as the summit and bwlch have now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes. 

The Trimble GeoXH 6000 gathering data at the bwlch of Pen yr Allt

The Trimble GeoXH 6000 gathering data at the summit of Pen yr Allt

Therefore, the confirmation of the addition of this hill to 200m Sub-Twmpau status is due to LIDAR summit analysis and a subsequent Trimble GeoXH 6000 survey, resulting in a 266.6m summit height and a 241.9m bwlch height, with these values giving this hill 24.7m of drop, which is sufficient for it to be classified as a 200m Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Pumlumon 

Name:  Pen yr Allt 

OS 1:50,000 map:  135, 136

Summit Height:  266.6m (converted to OSGM15) 

Summit Grid Reference:  SH 84232 02576 

Bwlch Height:  241.9m (converted to OSGM15) 

Bwlch Grid Reference:  SH 84202 02341 

Drop:  24.7m 

 

Myrddyn Phillips (July 2021)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Cefn Cyfronydd (SJ 144 082) – 200m Twmpau reclassified to 100m Twmpau (49th reclassification)

Survey post for Cefn Cyfronydd

There has been a reclassification to the list of 200m Twmpau and 100m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Cefn Cyfronydd (SJ 144 082) on the left

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

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

The 200m Twmpau by Myrddyn Phillips

100m Twmpau – Welsh hills at or above 100m and below 200m in height that have 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 100m and below 200m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 100m Twmpau by Myrddyn Phillips

The name the hill is listed by is Cefn Cyfronydd and this was derived from local enquiry, and it is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is positioned with a minor road to its north, the B4389 road to its north-west, the A458 road to its south-west and the B4392 road to its east, and has the small town of Llanfair Caereinion towards the west south-west. 

When the original 200m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list and listed with an estimated c 200m summit height, based on interpolation of its uppermost 200m ring 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

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 Cefn Cyfronydd (SJ 144 082)

The result produced by LIDAR analysis gives this hill a 199.2m summit height, and as the summit has now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes. 

The Trimble GeoXH 6000 gathering data at the summit of Cefn Cyfronydd

Therefore, the reclassification of this hill from 200m Twmpau status is due to LIDAR analysis and a subsequent Trimble GeoXH 6000 survey, resulting in 45.5m of drop, with a 199.1m summit height and a 150.6m bwlch height, with the summit height confirming its 100m Twmpau status. 

 

The full details for the hill are: 

Group:  Carnedd Wen 

Name:  Cefn Cyfronydd 

OS 1:50,000 map:  125

Summit Height:  199.1m (converted to OSGM15, Trimble GeoXH 6000)                                                      

Summit Grid Reference:  SJ 14459 08297 (Trimble GeoXH 6000) 

Bwlch Height:  150.6m (LIDAR) 

Bwlch Grid Reference:  SJ 14997 08587 (LIDAR) 

Drop:  48.5m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (July 2021)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Cefn Uchaf (SJ 157 072) – 200m Twmpau reclassified to 200m Sub-Twmpau (48th reclassification)

Survey post for Cefn Uchaf

Significant Name Changes post for Cefn Uchaf

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Cefn Uchaf (SJ 157 072)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Cefn Uchaf and this was derived from the Tithe map, and it is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is positioned with the B4392 road to its north-west and the A458 road to its south, and has the town of Y Trallwng (Welshpool) towards the east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the main P30 list, as map details on the contemporary Ordnance Survey 1:25,000 Explorer map gave this hill a 262m spot height, whilst its adjacent hill now listed as Quarry Field and which is positioned at SJ 15530 07552 was not given a spot height and remained with just an uppermost 260m ring contour. 

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

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 54m of drop based on the 262m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 208m bwlch height based on interpolation of 10m contouring.  With an adjacent hill now listed as Quarry Field (SJ 155 075) listed with an estimated c 25m of drop, based on an estimated c 262m summit height and an estimated c 237m bwlch height, with both heights based on interpolation of 10m contouring that appear on the Ordnance Survey 1:25,000 Explorer map. 

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and for the area taking in this hill it also had contouring at 5m intervals with an uppermost 265m contour given the adjacent hill of Quarry Field, with interpolation giving an estimated c 266m summit height and as this is higher than the 262m summit spot height given Cefn Uchaf the bylchau were swapped and each hill was reclassified. 

LIDAR image of Cefn Uchaf (SJ 157 072)

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

The Trimble GeoXH 6000 gathering data at the summit of Cefn Uchaf

LIDAR analysis confirms Cefn Uchaf as lower than Quarry Field and as the summit of both hills have now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes. 

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

Cefn Uchaf:  261.8m at SJ 15739 07264 

Quarry Field:  268.5m at SJ 15530 07552 

 

Therefore, the confirmation of the reclassification of this hill from 200m Twmpau status is due to LIDAR analysis and a subsequent Trimble GeoXH 6000 survey, resulting in a 261.8m summit height and a 235.1m bwlch height, with these values giving this hill 26.6m of drop, and therefore it is reclassified to a 200m Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Carnedd Wen 

Name:  Cefn Uchaf 

OS 1:50,000 map:  125

Summit Height:  261.8m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SJ 15739 07264 (Trimble GeoXH 6000) 

Bwlch Height:  235.1m (LIDAR) 

Bwlch Grid Reference:  SJ 15745 07416 (LIDAR) 

Drop:  26.6m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (June 2021)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Quarry Field (SJ 155 075) – 200m Sub-Twmpau reclassified to 200m Twmpau (47th reclassification)

Survey post for Quarry Field

Significant Height Revisions post for Quarry Field

Significant Name Changes post for Quarry Field

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips.

Quarry Field (SJ 155 075)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Quarry Field and this was derived from the Tithe map, and it is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is positioned with the B4392 road to its north-west and the A458 road to its south, and has the town of Y Trallwng (Welshpool) towards the east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 25m of drop, based on an estimated c 262m summit height and an estimated c 237m bwlch height, with both heights based on interpolation of 10m contouring that appear on the Ordnance Survey 1:25,000 Explorer map.  With an adjacent hill now listed as Cefn Uchaf (SJ 157 072) given a summit height of 262m based on the spot height that appears on contemporary Ordnance Survey 1:25,000 Explorer maps. 

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

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and for the area taking in this hill it also had contouring at 5m intervals with an uppermost 265m contour, with interpolation giving an estimated c 266m summit height and as this is higher than the 262m summit spot height given Cefn Uchaf the bylchau were swapped and each hill was reclassified. 

LIDAR image of Quarry Field (SJ 155 075)

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

The Trimble GeoXH 6000 gathering data at the summit of Quarry Field

LIDAR analysis confirms Quarry Field as higher than Cefn Uchaf and as the summit of both hills have now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes.

 

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

Quarry Field:  268.5m at SJ 15530 07552 

Cefn Uchaf:  261.8m at SJ 15739 07264 

 

Therefore, the confirmation of the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis and a subsequent Trimble GeoXH 6000 survey, resulting in a 268.5m summit height and a 209.6m bwlch height, with these values giving this hill 58.9m of drop, which is sufficient for it to be classified as a 200m Twmpau.

 

The full details for the hill are: 

Group:  Carnedd Wen 

Name:  Quarry Field 

OS 1:50,000 map:  125

Summit Height:  268.5m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SJ 15530 07552 (Trimble GeoXH 6000) 

Bwlch Height:  209.6m (LIDAR) 

Bwlch Grid Reference:  SJ 16489 07601 (LIDAR) 

Drop:  58.9m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (June 2021)

 

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Cae Pen y Maen (SN 656 694) – 200m Twmpau reclassified to 200m Sub-Twmpau (46th reclassification)

Survey post for Cae Pen y Maen

Significant Name Changes post for Cae Pen y Maen

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

LIDAR image of Cae Pen y Maen (SN 656 694)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Cae Pen y Maen and this was derived from the Tithe map, and it is adjoined to the Elenydd group of hills which are situated in the central part of the Mid and West Wales Region (Region B, Sub-Region B2), and it is positioned with the A485 road to its west, the B4575 road farther to its north, the B4340 road to its east and a minor road to its immediate north, and has the village of Lledrod towards the north-west. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the main P30 list with a summit height of 297m. 

When the accompanying sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 90m of drop, based on the 297m summit spot height and an estimated c 207m bwlch height, based on interpolation of 10m contouring between 200m – 210m that appear on the Ordnance Survey 1:25,000 Explorer map.  With an adjacent hill now listed as Banc y Maen Rochorlem (SN 675 691) given an estimated c 28m of drop, based on an estimated c 296m summit height and an estimated c 268m bwlch height, with both heights based on interpolation of 10m contouring that appear on the Ordnance Survey 1:25,000 Explorer map. 

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

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and for Banc y Maen Rochorlem a 299m spot height was given on the area of its summit and as this is higher than the 297m spot height given Cae Pen y Maen the bylchau were swapped and each hill was reclassified. 

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

LIDAR analysis confirmed Banc y Maen Rochorlem as the higher summit and gives Cae Pen y Maen a summit height of 296.6m, and as the summit has now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes. 

The Trimble GeoXH 6000 gathering data at the bwlch of Cae Pen y Maen

The Trimble GeoXH 6000 gathering data at the summit of Cae Pen y Maen

Prior to the Trimble GeoXH 6000 summit survey of this hill, the summit of Banc y Maen Rochorlem had also been surveyed and each result is given below: 

 

Banc y Maen Rochorlem:  299.3m at SN 67513 69184 

Cae Pen y Maen:  296.6m at SN 65690 69496 

 

Therefore, the confirmation of the reclassification of this hill to 200m Sub-Twmpau status is due to LIDAR analysis and a subsequent Trimble GeoXH 6000 survey, resulting in a 296.6m summit height and a 268.8m bwlch height, with these values giving this hill 27.9m of drop, which is insufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Elenydd 

Name:  Cae Pen y Maen 

OS 1:50,000 map:  135

Summit Height:  296.6m (converted to OSGM15) 

Summit Grid Reference:  SN 65690 69496 

Bwlch Height:  268.8m (converted to OSGM15) 

Bwlch Grid Reference:  SN 66401 68910 

Drop:  27.9m 

 

Myrddyn Phillips (May 2021)

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Banc y Maen Rochorlem (SN 675 691) – 200m Sub-Twmpau reclassified to 200m Twmpau (45th reclassification)

Survey post for Banc y Maen Rochorlem

Significant Height Revisions post for Banc y Maen Rochorlem

Summit Relocations post for Banc y Maen Rochorlem

Significant Name Changes post for Banc y Maen Rochorlem

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

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

The criteria for the list that this reclassification applies to are: 

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

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

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

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

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

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and for this hill a 299m spot height was given on the area of its summit and as this is higher than the 297m spot height given Cae Pen y Maen the bylchau were swapped and each hill was reclassified. 

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

LIDAR image of Banc y Maen Rochorlem (SN 675 691)

LIDAR analysis confirmed Cae Pen y Maen as the lower summit and gives Banc y Maen Rochorlem a summit height of 299.4m, and as the summit has now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes. 

The Trimble GeoXH 6000 gathering data at the natural high point of Banc y Maen Rochorlem

Since the Trimble GeoXH 6000 summit survey of this hill, the summit of Cae Pen y Maen has also been surveyed and each result is given below: 

 

Banc y Maen Rochorlem:  299.3m at SN 67513 69184 

Cae Pen y Maen:  296.6m at SN 65690 69496 

 

Therefore, the confirmation of the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis and a subsequent Trimble GeoXH 6000 survey, resulting in a 299.3m summit height and a 206.2m bwlch height, with these values giving this hill 93.1m of drop, which is sufficient for it to be classified as a 200m Twmpau.

 

The full details for the hill are: 

Group:  Elenydd 

Name:  Banc y Maen Rochorlem 

OS 1:50,000 map:  135

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

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

Bwlch Height:  206.2m (LIDAR) 

Bwlch Grid Reference:  SN 69578 68344 (LIDAR) 

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

 

Myrddyn Phillips (April 2021)

 

  

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Maes y Cefn (SN 797 954) – 200m Sub-Twmpau reclassified to 200m Twmpau (44th reclassification)

Significant Name Changes post for Maes y Cefn

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Maes y Cefn (SN 797 954)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Maes y Cefn and this was derived from the Tithe map, and it is adjoined to the Pumlumon group of hills, which are situated in the north-western part of Mid and West Wales (Region B, Sub-Region B2), and it has the A489 road to its north, the A487 road to its west and the B4518 road to its east, and has the village of Aberhosan towards the north north-east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 30m of drop, based on the 252m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 222m bwlch height, based on interpolation of 10m contouring between 220m – 230m that appear on the Ordnance Survey 1:25,000 Explorer map. 

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

The details for this hill were later re-assessed and its bwlch height was amended to an estimated c 221m with this giving the hill an estimated c 31m of drop. 

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

LIDAR gives the height of the critical point of a field boundary that crosses the bwlch in a hill to hill direction as 221.0m positioned at SN 79489 95118, as this is considered a relatively recent man-made construct it is discounted from the height of the bwlch.  LIDAR also gives the natural ground at the immediate base of this field boundary as being 220.9m in height; therefore it is this height that is taken for that of the bwlch. 

Therefore, the confirmation of the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 250.9m summit height and a 220.9m bwlch height, with these values giving this hill 30.0m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Pumlumon 

Name:  Maes y Cefn 

OS 1:50,000 map:  135

Summit Height:  250.9m (LIDAR) 

Summit Grid Reference:  SN 79761 95462 (LIDAR) 

Bwlch Height:  220.9m (LIDAR) 

Bwlch Grid Reference:  SN 79484 95138 (LIDAR) 

Drop:  30.0m (LIDAR) 

 

Myrddyn Phillips (March 2021)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Foel Fryniau (SH 633 306) – 200m Sub-Twmpau reclassified to 200m Twmpau (43rd reclassification)

There has been a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived by Joe Nuttall who produced a summit analysis programme using LIDAR, and then by LIDAR analysis initially conducted by Jim Bloomer and subsequently by Myrddyn Phillips. 

LIDAR image of Foel Fryniau (SH 633 306)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Foel Fryniau and it is adjoined to the Rhinogydd group of hills, which are situated in the western part of North Wales (Region A, Sub-Region A3), and it has the A496 road to its west and the A470 road to its east, and has the town of Harlech towards the west. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 26m of drop, based on the 222m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 196m bwlch height, based on interpolation of 10m contouring between 190m – 200m.  When The Welsh P15s list was being compiled the details for this hill were again reassessed and its drop value amended from c 26m to an estimated c 27m. 

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. 

Therefore, the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 221.0m summit height and a 190.2m bwlch height, with these values giving this hill 30.8m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Rhinogydd 

Name:  Foel Fryniau 

OS 1:50,000 map:  124

Summit Height:  221.0m (LIDAR) 

Summit Grid Reference:  SH 63325 30662 (LIDAR) 

Bwlch Height:  190.2m (LIDAR) 

Bwlch Grid Reference:  SH 63515 30647 (LIDAR) 

Drop:  30.8m (LIDAR) 

 

Myrddyn Phillips (March 2021)

 

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Ffridd (SN 808 977) – 200m Sub-Twmpau reclassified to 200m Twmpau (42nd reclassification)

Significant Name Changes post for Ffridd

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Ffridd (SN 808 977)

The criteria for the list that this reclassification applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Ffridd and this was derived from the Tithe map, and it is adjoined to the Pumlumon group of hills, which are situated in the north-western part of Mid and West Wales (Region B, Sub-Region B2), and it is encircled by minor roads and tracks with the B4518 road further to the east, the A470 road further to the north-east, the A489 road further to the north-west and the A487 road further to the west, and has the town of Machynlleth towards the north-west. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 33m of drop, based on an estimated c 236m summit height and an estimated c 233m bwlch height, with each height based on interpolation from 10m contouring on the Ordnance Survey 1:25,000 Explorer map. 

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

Since publication of these P30 lists on Geoff Crowder’s v-g.me website there have been a number of Ordnance Survey maps made available online, some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website, whilst others are current and digitally updated such as the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map.  This mapping had many spot heights not on other publicly available Ordnance Survey maps, and for this hill it showed a 237m spot height on the area of its summit. 

Another resource available online is the interactive mapping originated from Ordnance Survey data hosted on the Magic Maps website.  This mapping also shows a 237m spot height on the summit area of this hill. 

Extract from the Magic Maps website

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

Therefore, the confirmation of the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 236.6m summit height and a 202.5m bwlch height, with these values giving this hill 34.1m of drop, which is sufficient for it to be classified as a 200m Twmpau. 

 

The full details for the hill are: 

Group:  Pumlumon 

Name:  Ffridd 

OS 1:50,000 map:  135, 136

Summit Height:  236.6m (LIDAR) 

Summit Grid Reference:  SN 80899 97705 (LIDAR) 

Bwlch Height:  202.5m (LIDAR) 

Bwlch Grid Reference:  SN 81383 97749 (LIDAR) 

Drop:  34.1m (LIDAR) 

 

Myrddyn Phillips (March 2021)

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Castle Hill (SO 314 945) – 200m Sub-Twmpau addition (41st reclassification)

Survey post for Castle Hill

Significant Height Revisions post for Castle Hill

There has been confirmation of an addition to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data and a Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

The criteria for the list that this addition applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Castle Hill and it is adjoined to the Stiperstones group of hills, which straddle the border between Wales and England with the Welsh part of this group situated in the north-eastern part of Mid and West Wales (Region B, Sub-Region B1), and it is positioned with the A490 road to its west, the A489 road to its south and the A488 road to its east, and has the small community of Hyssington towards the south-west. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was not included in the accompanying Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category. 

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 24m of drop, based on an estimated c 281m summit height and the 257m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was named the Interactive Coverage Map. 

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

Since the original compilation of this list there have been a number of Ordnance Survey maps made available online, some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website, whilst others are current and digitally updated such as the mapping on the WalkLakes website and 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 map has many spot heights not on other publicly available Ordnance Survey maps and for this hill a 283m spot height is given on the area of its summit. 

Extract from the Magic Maps website

The details for this hill were also re-assessed against the mapping on the OS Maps website.  This is the replacement for OS Get-a-map and until recent times had contours at 5m intervals which were proving consistently more accurate compared to the 5m contours that sometimes appear on the Ordnance Survey 1:25,000 Explorer map and used to appear on the online Vector Map Local.  This resulted in its bwlch height being estimated as c 261m based on interpolation of 5m contouring between 260m – 265m. 

The Trimble GeoXH 6000 gathering data at the summit of Castle Hill

Therefore, the confirmation of the addition of this hill to 200m Sub-Twmpau status is due to detail on contemporary maps produced from Ordnance Survey data and a Trimble GeoXH 6000 summit survey, resulting in a 283.2m summit height and an estimated c 261m bwlch height, with these values giving this hill an estimated c 22m of drop, which is sufficient for it to be classified as a 200m Sub-Twmpau.

 

The full details for the hill are: 

Group:  Stiperstones 

Name:  Castle Hill 

OS 1:50,000 map:  137

Summit Height:  283.2m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SO 31430 94540 (Trimble GeoXH 6000) 

Bwlch Height:  c 261m (interpolation) 

Bwlch Grid Reference:  SO 31356 94661 (interpolation) 

Drop:  c 22m (Trimble GeoXH 6000 summit and interpolated bwlch) 

 

Myrddyn Phillips (March 2021)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Mynydd Cefn Maes Mawr (SN 728 985) – 200m Sub-Twmpau reclassified to 200m Twmpau (40th reclassification)

Significant Name Changes post for Mynydd Cefn Maes Mawr

There has been confirmation of a reclassification to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Mynydd Cefn Maes Mawr (SN 728 985)

The criteria for the list that this reclassification applies to are: 

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

200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Mynydd Cefn Maes Mawr and this was derived from the Tithe map, and it is adjoined to the Banc Llechwedd Mawr group of hills, which are situated in the north-western part of South Wales (Region B, Sub-Region B1), and it is positioned with the A487 road to its north-west and minor roads to its south and east, and has the town of Machynlleth towards the north-east.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

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

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with 33m of drop, based on the 227m summit spot height and the 194m bwlch spot height that appeared on the Ordnance Survey Vector Map Local that was 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. 

Therefore, the confirmation of the reclassification of this hill from 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 227.0m summit height and a 193.2m bwlch height, with these values giving this hill 33.8m of drop, which is sufficient for it to be classified as a 200m Twmpau.

 

The full details for the hill are: 

Group:  Banc Llechwedd Mawr 

Name:  Mynydd Cefn Maes Mawr 

OS 1:50,000 map:  135

Summit Height:  227.0m (LIDAR) 

Summit Grid Reference:  SN 72879 98501 (LIDAR) 

Bwlch Height:  193.2m (LIDAR) 

Bwlch Grid Reference:  SN 73168 98304 (LIDAR) 

Drop:  33.8m (LIDAR)

 

Myrddyn Phillips (February 2021)

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Henfaes Common (SO 120 974) – 200m Sub-Twmpau deletion (39th reclassification)

Survey post for Henfaes Common

Significant Name Changes post for Henfaes Common

There has been a deletion to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Henfaes Common (SO 120 974)

The criteria for the list that this deletion applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Henfaes Common and this was derived from the Tithe map, and it is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is positioned with the B4390 road to its north, the B4389 road to its south and the A483 road to its east, and has the village of Betws Cedewain towards the south. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was not included in the accompanying Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with 20m of drop, based on the 214m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map, and the 194m bwlch spot height that appeared on the Ordnance Survey Vector Map Local that was 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 image of Henfaes Common

The result produced by LIDAR analysis gives this hill 16.4m of drop, and as the summit has now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes. 

The Trimble GeoXH 6000 gathering data at the summit of Henfaes Common

Therefore, the deletion of this hill from 200m Sub-Twmpau status is due to LIDAR analysis and a Trimble GeoXH 6000 survey, resulting in a 215.2m summit height and a 198.8m bwlch height, with these values giving this hill 16.4m of drop, which is insufficient for it to be classified as a 200m Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Carnedd Wen 

Name:  Henfaes Common 

OS 1:50,000 map:  137

Summit Height:  215.2m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SO 12003 97409 (Trimble GeoXH 6000) 

Bwlch Height:  198.8m (LIDAR) 

Bwlch Grid Reference:  SO 12171 97587 (LIDAR) 

Drop:  16.4m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (February 2021)

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Pt. 218.8m (SO 122 978) – 200m Sub-Twmpau deletion (38th reclassification)

Survey post for Pt. 218.8m

Significant Height Revisions post for Pt. 218.8m

There has been a deletion to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Pt. 218.8m (SO 122 978)

The criteria for the list that this deletion applies to are: 

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

The 200m Twmpau by Myrddyn Phillips

The hill is being listed by the point (Pt. 218.8m) 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 Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is positioned with minor roads to its south-east and north, and has the B4389 road to its south-west, and has the small community of Betws Cedewain towards the south. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the accompanying Hills to be surveyed sub list, and listed with an estimated c 230m summit height. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 27m of drop, based on an estimated c 231m summit height and a 204m bwlch height, with the latter based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map.  An anomaly was also noted with the heights given the contours on the upper part of this hill on the 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 Pt. 218.8m

The result produced by LIDAR analysis gives this hill a 218.8m summit height and 13.6m of drop, confirming that the uppermost contour on the 1:25,000 Explorer map is not 230m, and as the summit has now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes. 

The Trimble GeoXH 6000 gathering data at the summit of Pt. 218.8m

Therefore, the deletion of this hill from 200m Sub-Twmpau status is due to LIDAR analysis and a Trimble GeoXH 6000 survey, resulting in a 218.8m summit height and a 205.3m bwlch height, with these values giving this hill 13.5m of drop, which is insufficient for it to be classified as a 200m Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Carnedd Wen 

Name:  Pt. 218.8m 

OS 1:50,000 map:  136

Summit Height:  218.8m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SO 12216 97806 (Trimble GeoXH 6000) 

Bwlch Height:  205.3m (LIDAR) 

Bwlch Grid Reference:  SO 12899 97950 (LIDAR) 

Drop:  13.5m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (January 2021)

 

 

 

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Sixteen Acres (SO 120 987) – 200m Sub-Twmpau addition (37th reclassification)

Survey post for Sixteen Acres

Significant Name Changes post for Sixteen Acres

Significant Height Revisions post for Sixteen Acres

There has been confirmation of an addition to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips.

Sixteen Acres (SO 120 987)

The criteria for the list that this addition applies to are:

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

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Sixteen Acres and this was derived from local enquiry, and it is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is positioned with the B4390 road to its north, the B4389 road to its west and the A483 road further to its south-east, and has the village of Tregynon towards the west.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was not included in the accompanying Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category. 

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 20m of drop, based on an estimated c 216m summit height and the 196m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was named the Interactive Coverage Map.

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

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

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 Ordnance Survey maps and for this hill a 219m spot height is given on the area of its summit.

Extract from the WalkLakes website

Another resource available online is the interactive mapping originated from Ordnance Survey data hosted on the Magic Maps website.  This mapping also shows a 219m spot height on the summit area of this hill.

Extract from the Magic Maps website

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

LIDAR image of Sixteen Acres

The result produced by LIDAR analysis gives this hill 20.1m of drop, and as the summit has now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes.

The Trimble GeoXH 6000 gathering data at the summit of Sixteen Acres

Therefore, the confirmation of the addition of this hill to 200m Sub-Twmpau status is due to LIDAR analysis and a Trimble GeoXH 6000 survey, resulting in a 219.2m summit height and a 199.1m bwlch height, with these values giving this hill 20.1m of drop, which is sufficient for it to be classified as a 200m Sub-Twmpau.

The full details for the hill are:

Group:  Carnedd Wen

Name:  Sixteen Acres

OS 1:50,000 map:  136

Summit Height:  219.2m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SO 12005 98756 (Trimble GeoXH 6000)

Bwlch Height:  199.1m (LIDAR)

Bwlch Grid Reference:  SO 11953 98547 (LIDAR)

Drop:  20.1m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Myrddyn Phillips (December 2020)

Mapping Mountains - Hill Reclassifications - 200m Twmpau

Pt. 243.8m (SJ 084 023) – 200m Sub-Twmpau deletion (36th reclassification)

Survey post for Pt. 243.8m

There has been a deletion to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips.

Pt. 243.8m (SJ 084 023)

The criteria for the list that this deletion applies to are:

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

The 200m Twmpau by Myrddyn Phillips

The hill is being listed by the point (Pt. 243.8m) 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 Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is situated with minor roads to its north, west and south and has the B4389 road to its east, and has the small community of Felin Newydd (New Mills) towards the south-east.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was not included in the accompanying Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 21m of drop, based on an estimated c 245m summit height and an estimated c 224m 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 image of Pt. 243.8m (SJ 084 023)

The result produced by LIDAR analysis gives this hill 19.0m of drop, and as the summit has now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes.

The Trimble GeoXH 6000 gathering data at the summit of Pt. 243.8m

Therefore, the deletion of this hill from 200m Sub-Twmpau status is due to LIDAR analysis and a Trimble GeoXH 6000 survey, resulting in a 243.8m summit height and a 224.8m bwlch height, with these values giving this hill 19.0m of drop, which is insufficient for it to be classified as a 200m Sub-Twmpau.

The full details for the hill are:

Group:  Carnedd Wen

Name:  Pt. 243.8m

OS 1:50,000 map:  136

Summit Height:  243.8m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SJ 08450 02373 (Trimble GeoXH 6000)

Bwlch Height:  224.8m (LIDAR)

Bwlch Grid Reference:  SJ 08279 02691 (LIDAR)

Drop:  19.0m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Myrddyn Phillips (December 2020)