Mapping Mountains – Hill Reclassifications – The Welsh P15s

 

Pt. 32.8m (SN 531 017) – 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. 32.8m (SN 531 017)

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 10^th May 2019. 

The Welsh P15s by Myrddyn Phillips

The hill is being listed by the point (Pt. 32.8m) notation, and it is adjoined to the Mynydd Sylen group of hills, which are situated in the southern part of South Wales (Region B, Sub-Region B5), and it is positioned with the B4303 road to its north, a minor road to its south-west and the A4138 road to its south-east, and has the town of Llanelli towards the south-west.

When the listing that became known as The Welsh P15s was being compiled, this hill was included in the main P15 list with an estimated c 15m of drop, based on an estimated c 34m summit height and an estimated c 19m bwlch heights, with both heights based on interpolation of 5m 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 deletion of this hill from Welsh P15 status is due to LIDAR analysis, resulting in a 32.8m summit height and a 21.4m bwlch height, with these values giving this hill 11.4m 0f drop, which is insufficient for it to be classified as a Welsh P15. 

 

The full details for the hill are: 

Group:  Mynydd Sylen 

Name:  Pt. 32.8m 

OS 1:50,000 map:  159

Summit Height:  32.8m (LIDAR)                                                           

Summit Grid Reference:  SN 53114 01761 (LIDAR)                                                  

Bwlch Height:  21.4m (LIDAR) 

Bwlch Grid Reference:  SN 53089 02006 (LIDAR) 

Drop:  11.4m (LIDAR) 

 

Myrddyn Phillips (January 2025)