Mapping Mountains – Significant Name Changes – 200m Twmpau

 

Pen y Bryn (SO 075 896) 

There has been a Significant Name Change to a hill that is listed in the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Pen y Bryn (SO 075 896)

The criteria for the list that this name change 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.  The list is authored by Myrddyn Phillips, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

200m Twmpau by Myrddyn Phillips

The hill is adjoined to the Hirddywel group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B2), and it is positioned with minor roads to its west, south and east, and the A489 road to its north-east, and has the town of Y Drenewydd (Newtown) towards the east north-east.

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

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed under the point (Pt. 239m) notation with 27m of drop, based on the 239m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 212m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

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

As the summit of this hill comprises bounded land the details for it were examined on the Tithe map.  The term Tithe map is generally given to a map of a Welsh or English parish or township and which was prepared after the 1836 Tithe Commutation Act.  This act allowed tithes to be paid in cash rather than goods.  The Tithe maps gave names of owners and occupiers of land in each parish and importantly for place-name research they also included the name of enclosed land.  This enclosed land is usually based on a field system, however not every field is given a name, but many are and especially so in Wales. 

Extract from the Tithe map

The enclosed land where the summit of this hill is situated is given the number 246 on the Tithe map, this can be cross referenced against the apportionments; it is these apportionments that give the name of the owner or occupier of the land as well as the name of the land.  The land where the summit of this hill is situated is named as a part of Pen y Bank farm in the apportionments, with this a probable typo for Pen y Bryn, which it appears as on the Tithe map, with the details on the Tithe map appearing in the parish named as Penstrowed and in the county named as Montgomery. 

Extract from the apportionments

Therefore, the name this hill is now listed by in the 200m Twmpau is Pen y Bryn, and this was derived from the Tithe map. 

 

The full details for the hill are:

Group:  Hirddywel

Name:  Pen y Bryn

Previously Listed Name:  Pt. 239m   

OS 1:50,000 map:  136

Summit Height:  238.6m (LIDAR) 

Summit Grid Reference:  SO 07529 89658 (LIDAR) 

Bwlch Height:  210.5m (LIDAR) 

Bwlch Grid Reference:  SO 07074 89710 (LIDAR) 

Drop:  28.1m (LIDAR) 

 

Myrddyn Phillips (April 2025)

 

 

Mapping Mountains – Summit Relocations – The Welsh P15s

Cae Cwar y Tŷ (SN 907 499) 

There has been a Summit Relocation to a hill that is listed in the The Welsh P15s, 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 Cwar y Tŷ (SN 907 499)

The criteria for the list that this summit relocation 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

The name the hill is now listed by is Cae Cwar y Tŷ, 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 South Wales (Region B, Sub-Region B1), and it is positioned with the A483 road to its north and a minor road to its south-west and east, and has the town of Llanwrtyd towards the south-west.

When the listing that became known as The Welsh P15s was being compiled, this hill was included in the accompanying sub list with 14m of drop, based on the 257m summit spot height positioned at SN 90720 49939 and the 243m bwlch spot height, both of which appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

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

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

LIDAR analysis gives the highest ground on this hill as 259.1m positioned at SN 90712 49930 and SN 90717 49931.  However, this is to the top of a raised field boundary and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill. 

LIDAR summit image of Cae Cwar y Tŷ (SN 907 499)

The height produced by LIDAR analysis to the natural summit of this hill is 259.0m and is positioned at SN 90705 49957, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

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

Therefore, the summit height produced by LIDAR analysis is 259.0m and is positioned at SN 90705 49957, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is approximately 18 metres north-westward from where the 257m spot height was positioned and approximately 26 metres north-westward from the high point of the raised field boundary. 

 

The full details for the hill are: 

Group:  Drygarn Fawr 

Name:  Cae Cwar y Tŷ 

OS 1:50,000 map:  147

Summit Height:  259.0m (LIDAR)                                                           

Summit Grid Reference (New Position):  SN 90705 49957 (LIDAR)                                                  

Bwlch Height:  243.4m (LIDAR) 

Bwlch Grid Reference:  SN 90715 49674 & SN 90716 49675 (LIDAR) 

Drop:  15.6m (LIDAR) 

 

Myrddyn Phillips (April 2025)

  

Mapping Mountains – Hill Reclassifications – 100m Twmpau

 

Creigiau Cochion (SN 611 989) – 100m Sub-Twmpau deletion

There has been a deletion from the list of 100m 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 Creigiau Cochion (SN 611 989)

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

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.  The list is authored by Myrddyn Phillips, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

100m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Creigiau Cochion and this was derived from the Tithe map, and it is adjoined to the Tarren y Gesail group of hills, which are situated in the south-western part of North Wales (Region A, Sub-Region A3), and it is positioned with a minor road to its north and the A493 road to its west and south, and has the town of Tywyn towards the north-west.

When the original 100m 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-assessed and it was listed with an estimate c 20m of drop, based on the 168m summit spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map and an estimated c 148m bwlch height, based on interpolation of 10m contouring between 140m – 150m. 

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 deletion of this hill from 100m Sub-Twmpau status is due to LIDAR analysis, resulting in a 168.3m summit height and a 148.3m bwlch height, with these values giving this hill 19.98m of drop, which is insufficient for it to be classified as a 100m Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Tarren y Gesail 

Name:  Creigiau Cochion 

OS 1:50,000 map:  135

Summit Height:  168.3m (LIDAR) 

Summit Grid Reference:  SN 61176 98937 (LIDAR) 

Bwlch Height:  148.3m (LIDAR) 

Bwlch Grid Reference:  SN 61236 98904 (LIDAR) 

Drop:  19.98m (LIDAR) 

 

Myrddyn Phillips (April 2025)

 

Monthly Synopsis

 

Synopsis of all major changes detailed on Mapping Mountains during the last calendar month.  These can include new, confirmation and retrospective changes

 

Hill Reclassifications: 

Parc Penrhyn (SH 601 720) - 30-99m Sub-Twmpau addition

Cae Cefn (SO 315 009) - 100m Sub-Twmpau addition

Ffridd (SN 730 979) - 200m Sub-Twmpau deletion

Woodend Height (SD 156 954) - Sub-Four addition

Middletwon Hill (SJ 298 130) - Sub-Trichant addition

Ffridd (SN 727 981) - 200m Sub-Twmpau deletion

Graig Fach (SH 792 249) - Welsh Highland Sub reinstatement

Cae Cwar y Tŷ (SN 907 499) - Welsh Sub-P15 reclassified to Welsh P15

Pen y Bryn (SO 075 896) - 200m Sub-Twmpau addition

Gowbarrow Park (NY 408 212) - Sub-Four exclusion

New Field (SJ 257 0540) - Sub-Trichant addition

Rhos Uchaf (SH 593 699) - 30-99m Sub-Twmpau addition

Pt. 474.4m (NY 381 113) - Sub-Four exclusion

Significant Height Revisions: 

Parc Penrhyn (SH 601 720) - 30-99m Twmpau

Cae Cefn (SO 315 009) - 100m Twmpau

Woodend Height (SD 156 954) - The Fours - The 400m Hills of England

Cae Cwar y Tŷ (SN 907 499) - The Welsh P15s

Summit Relocations: 

Cae Pant (SN 908 472) - The Welsh P15s

Cae Cefn (SO 315 009) - 100m Twmpau

Pen y Bryn (SO 075 896) - 200m Twmpau

Rhos Uchaf (SH 593 699) - 30-99m Twmpau

Significant Name Changes: 

Cefn y Castell (SJ 305 133) - Y Trichant - The 300m Hills of Wales

Pt. 428.9m (SO 035 449) - Y Pedwarau - The 400m Hills of Wales

Cae Pant (SN 908 472) - The Welsh P15s

Breiddin (SJ 295 144) - Y Trichant - The 300m Hills of Wales

Parc Penrhyn (SH 601 720) - 30-99m Twmpau

Cae Cefn (SO 315 009) - 100m Twmpau

Pt. 423.1m (SH 715 748) - The Welsh P15s

New Field (SJ 257 040) - Y Trichant - The 300m Hills of Wales

Mapping Mountains – Summit Relocations – 30-99m Twmpau

 

Rhos Uchaf (SH 593 699) 

There has been a Summit Relocation to a hill that is listed in the 30-99m 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 Rhos Uchaf (SH 593 699)

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

30-99m Twmpau – Welsh hills at or above 30m and below 100m in height that have 30m minimum drop, with an accompanying sub list entitled the 30-99m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 30m and below 100m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

30-99m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Rhos Uchaf, and this was derived from the Tithe map, and it is adjoined to the Glyder Fawr group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with the A5 road to its immediate west and the A55 road to its south-east, and has the city of Bangor towards the north-west.

When the original 30-99m 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 16m of drop, based on an estimated c 93m summit height which was listed at SH 59346 69940 and an estimated c 77m bwlch height, with both heights based on interpolation of 5m contouring. 

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

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

LIDAR analysis gives the highest ground on this hill as 93.0m positioned at SH 59327 69929.  However, this is a part of a raised boundary edge and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill. 

LIDAR summit image of Rhos Uchaf (SH 593 699)

The height produced by LIDAR analysis to the highest remaining natural ground of this hill is 92.5m and this is positioned at SH 59332 69923, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

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

Therefore, the height produced by LIDAR analysis to the summit of this hill is 92.5m and is positioned at SH 59332 69923, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is approximately six metres south-eastward from where the high point of the raised boundary edge is positioned. 

 

The full details for the hill are: 

Group:  Glyder Fawr 

Name:  Rhos Uchaf 

OS 1:50,000 map:  114, 115

Summit Height:  92.5m (LIDAR) 

Summit Grid Reference (New Position):  SH 59332 69923 (LIDAR)               

Bwlch Height:  71.8m (LIDAR) 

Bwlch Grid Reference:  SH 59236 69468 (LIDAR) 

Drop:  20.7m (LIDAR) 

 

Myrddyn Phillips (March 2025)