Thursday, 1 May 2025

Mapping Mountains – Hill Reclassifications – The Welsh P15s


Pt. 322.6m (SN 329 350) – Welsh P15 deletion

There has been a deletion 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 Pt. 322.6m (SN 329 350)

The criteria for the list that this deletion 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 10th May 2019. 

The Welsh P15s by Myrddyn Phillips

The hill is being listed by the point (Pt. 322.6m) notation, 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 minor roads to its north, west and south, and the B4333 road to its east, and has the town of Castellnewydd Emlyn (Newcastle Emlyn) towards the north north-west.

When the listing that became known as The Welsh P15s was being compiled, this hill was included in the main list with an estimated c 15m of drop, based on the 323m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map, and an estimated c 308m bwlch height, based on interpolation of 5m contouring between 305m – 310m. 

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 Welsh P15 status is due to LIDAR analysis, resulting in a 322.6m summit height and a 308.8m bwlch height, with these values giving this hill 13.8m 0f drop, which is insufficient for it to be classified as a Welsh P15. 

 

The full details for the hill are: 

Group:  Mynydd Pencarreg 

Name:  Pt. 322.6m 

OS 1:50,000 map:  145

Summit Height:  322.6m (LIDAR)                                                           

Summit Grid Reference:  SN 32934 35049 (LIDAR)                                                  

Bwlch Height:  308.8m (LIDAR) 

Bwlch Grid Reference:  SN 32770 34496 (LIDAR) 

Drop:  13.8m (LIDAR) 

 

Myrddyn Phillips (May 2025) 

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