Mapping Mountains – Hill Reclassifications – The Welsh P15s

 

Cae Cefn Issa (SN 692 009) – Welsh P15 addition 

There has been an addition to the list of 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 Cefn Issa (SH 692 009)

The criteria for the list that this addition 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 listed by is Cae Cefn Issa, 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 the A493 road to its south, and has the town of Machynlleth towards the east.

When the listing that became known as The Welsh P15s was being compiled, this hill was not included in either the main list or the accompanying sub list, and was subsequently documented with an estimated c 13m of drop, based on an estimated c 120m summit height and an estimated c 107m bwlch height, with both heights based on interpolation of 10m contouring that appears on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the 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 addition of this hill to Welsh P15 status is due to LIDAR analysis, resulting in a 119.5m summit height and a 103.9m bwlch height, with these values giving this hill 15.5m 0f drop, which is sufficient for it to be classified as a Welsh P15. 

 

The full details for the hill are: 

Group:  Tarren y Gesail 

Name:  Cae Cefn Issa 

OS 1:50,000 map:  135

Summit Height:  119.5m (LIDAR)                                                           

Summit Grid Reference:  SH 69202 00955 (LIDAR)                                                  

Bwlch Height:  103.9m (LIDAR) 

Bwlch Grid Reference:  SH 69081 01055 (LIDAR) 

Drop:  15.5m (LIDAR) 

 

Myrddyn Phillips (December 2025)

Mapping Mountains – Hill Reclassifications – Y Pedwarau – The 400m Hills of Wales

Cefn y Bryn (SN 705 429) – 400m Sub-Pedwar addition

There has been an addition to the listing of the Y Pedwarau – The 400m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cefn y Bryn (SN 705 429)

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

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

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

The name the hill is listed by is Cefn y Bryn, and it is adjoined to the Mynydd Mallaen group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned with a minor road to its west and south, and the A482 road farther to its west, and has the village of Llanwrda towards the south.

When the original 400m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category.

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 19m of drop, based on the 410m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and an estimated c 391m bwlch height, based on interpolation of 10m contouring between 390m – 400m. 

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 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.

Another resource now available online is the interactive mapping hosted on the Welsh Government website and entitled the DataMapWales.  This mapping has 5m contours and its detail matches that produced from the OS Terrain 5 product, which compliments much of that produced from LIDAR, and for this hill it has a 410m summit spot height and bwlch contouring between 385m – 390m. 

Extract from the DataMapWales

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 addition of this hill to 400m Sub-Pedwar status is due to LIDAR analysis, resulting in a 410.3m summit height and a 389.9m bwlch height, with these values giving this hill 20.4m of drop, which is sufficient for it to be classified as a 400m Sub-Pedwar.                                         

 

The full details for the hill are:

Group:  Mynydd Mallaen

Name:  Cefn y Bryn

OS 1:50,000 map:  146, 147, 160

Summit Height:  410.3m (LIDAR)

Summit Grid Reference:  SN 70571 42996 (LIDAR)

Bwlch Height:  389.9m (LIDAR)

Bwlch Grid Reference:  SN 70984 43313 (LIDAR)    

Drop:  20.4m (LIDAR) 

 

For the additions, reclassifications and deletions to Y Pedwarau – The 400m Hills of Wales reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:

 

Y Pedwarau

 

Y Pedwarau – 400m Sub-Pedwarau

 

Y Pedwarau – 390m Sub-Pedwarau

 

Y Pedwarau – 390m Double Sub-Pedwarau

 

Myrddyn Phillips and Aled Williams (December 2025) 

Mapping Mountains – Hill Reclassifications – The Fours – The 400m Hills of England

Eldon Hill Quarries (SK 115 815) – Sub-Four addition

There has been an addition to the listing of the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Eldon Hill Quarries (SK 115 815)

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

The Fours – The 400m Hills of England - English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list is a sub list entitled the Sub-Fours, the criteria for which are all English hills at or above 400m and below 500m in height that have 15m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available to download in Google Doc format from the Mapping Mountains site.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Eldon Hill Quarries, and it is adjoined to the Kinder Scout group of hills, which are situated in the Peak District, and it is positioned with a minor road to its north-west and the A623 road to its south, and has the town of Chapel-en-le-Frith towards the west.

When the Introduction to the first group of hills for the updated and revised listing of the The Fours – The 400m Hills of England was published by Mapping Mountains on the 10^th September 2022, it was announced that the accompanying sub lists were being revised with the two 390m categories dispensed with and the criteria and name of the 400m Sub-Fours revised.  The one accompanying sub list is now named the Sub-Fours with its criteria being all English hills 400m and above and below 500m in height that have 15m and more and below 30m of drop. 

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

Prior to this revision this hill was not listed, with subsequent interpolation giving it an estimated c 16m of drop, based on the 413m summit spot height that appears on the DataMapWales and an estimated c 397m col height, based on interpolation of 5m contouring between 395m – 400m. 

Extract from the DataMapWales

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 addition of this hill to Sub-Four status is due to LIDAR analysis, resulting in a 415.9m summit height and a 396.7m col height, with these values giving this hill 19.1m of drop, which is sufficient for it to be classified as a Sub-Four. 

 

The full details for the hill are:

Group:  Kinder Scout

Name:  Eldon Hill Quarries

OS 1:50,000 map:  110

Summit Height:  415.9m (LIDAR)

Summit Grid Reference:  SK 11562 81552 (LIDAR)

Col Height:  396.7m (LIDAR)

Col Grid Reference:  SK 11624 81555 (LIDAR)

Drop:  19.1m (LIDAR)

 

For the additions, deletions and reclassifications to The Fours – The 400m Hills of England reported on Mapping Mountains since the December 2013 publication of the 1^st edition of this list by Europeaklist please consult the following Change Registers:

 

The Fours

 

Sub-Fours

 

Myrddyn Phillips and Aled Williams (December 2025)              

Mapping Mountains – Significant Name Changes – 200m Twmpau

Cae Fron (SN 635 716) 

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 Cae Fron (SN 635 716)

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 Carn yr Hyrddod group of hills, which are situated in the north-western part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its north and south, and the A485 road to its east, and has the village of Lledrod 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 accompanying Hills to be surveyed sub list under the transposed name of Garth-fawr, with an accompanying note stating; Name from buildings to the North.

Garth-fawr

240m

SN635717

135

213

Name from buildings to the North

During my early hill listing I thought it appropriate to either invent a name for a hill or use a name that appeared near to the summit of the hill on Ordnance Survey maps of the day, with little consideration for the meaning of the name and where it was appropriately applied to.  My preference was to use farm names and put Pen, Bryn or Moel in front of them or as in this instance transpose the name of a farm and use it for that of the hill.  This is not a practice that I now advocate as with time and inclination place-name data can be improved either by asking local people or by examining historic documents, through this form of research an appropriate name for the hill can usually be found. 

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 258 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 Cae Fron in the apportionments, with the details on the Tithe map appearing in the parish named as Llangwyryfon and in the county named as Cardigan. 

Extract from the apportionments

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

 

The full details for the hill are:

Group:  Carn yr Hyrddod

Name:  Cae Fron

Previously Listed Name:  Garth-fawr   

OS 1:50,000 map:  135

Summit Height:  239.9m (LIDAR) 

Summit Grid Reference:  SN 63504 71673 & SN 63506 71673 & SN 63510 71671 (LIDAR) 

Bwlch Height:  214.3m (LIDAR) 

Bwlch Grid Reference:  SN 63774 71880 (LIDAR) 

Drop:  25.6m (LIDAR) 

 

Myrddyn Phillips (December 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: 

Rhiwlas Hill (SN 934 779) - 400m Sub-Four addition

Spence Moor (SD 794 393) - Sub-Four addition

Lurden Top (SD 989 121) - Sub-Four exclusion

Mynydd Perthi (SN 953 727) - 400m Sub-Pedwar addition

Cae Grib (SN 679 992) - Welsh P15 addition

Duckpit (SE 030 089) - Sub-Four exclusion

North Bishop (SM 667 278) - Double Sub-Twmpau deletion

Coed Cefn Coch (SH 670 000) - 100m Sub-Twmpau deletion

Totley Moor (SK 274 800) - Sub-Four addition

Coed Llwyn Owen (SN 703 402) - Sub-Trichant deletion

North Bishop (SM 666 277) - Double Sub-Twmpau deletion

Chinley Churn (SK 035 836) - Sub-Four exclusion

Ffridd (SN 662 982) - 100m Sub-Twmpau addition

Significant Height Revisions: 

Coed Felin Lodge (SN 663 932) - The Welsh P15s

North Bishop (SM 67087 28056) - 30-99m Twmpau, Y Trechol - The Dominant Hills of Wales and Y Pellennig - The Remotest Hills of Wales

Bryn Llwyn (SN 672 998) - 100m Twmpau

Lan Ddu (SN 716 388) - Y Trichant - The 300m Hills of Wales

Cae Grib (SN 679 992) - The Welsh P15s

Summit Relocations: 

Long Cae Maes (SO 312 933) - 200m Twmpau

Pt. 439.8m (SO 001 769) - Y Pedwarau - The 400m Hills of Wales

Coed Cefn Coch (SH 670 000) - The Welsh P15s

Significant Name Changes: 

Coed Felin Lodge (SN 663 932)- The Welsh P15s

Duckpit (SE 030 089) - The Fours - The 400m Hills of England

Long Cae Maes (SO 312 933) - 200m Twmpau

Cae Grib (SN 679 992) - The Welsh P15s

Coed Cefn Coch (SH 670 000) - The Welsh P15s