Mapping Mountains – Summit Relocations – The Welsh P15s

Parc Gwastod (SN 300 359) 

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 Parc Gwastod (SN 300 359)

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 Parc Gwastod, 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 B4333 road farther to its east, and has the town of Castellnewydd Emlyn (Newcastle Emlyn) towards the north.

When the listing that became known as The Welsh P15s was being compiled, this hill was included in the main list with 15m of drop, based on the 208m summit spot height positioned at SN 30119 35939 that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and the 193m 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

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 209.1m positioned at SN 30088 35919.  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 Parc Gwastod (SN 300 359)

The height produced by LIDAR analysis to the natural summit of this hill is 208.0m and is positioned at SN 30059 35918 and SN 30061 35921 and SN 30070 35947 and SN 30073 35949 and SN 30076 35949, 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 the de-twinning of a summit, 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 208.0m and is positioned at SN 30059 35918 and SN 30061 35921 and SN 30070 35947 and SN 30073 35949 and SN 30076 35949, 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 60 metres south-westward from where the 208m spot height is positioned and approximately 30 metres westward from the high point of the raised field boundary. 

 

The full details for the hill are: 

Group:  Mynydd Pencarreg 

Name:  Parc Gwastod 

OS 1:50,000 map:  145

Summit Height:  208.0m (LIDAR)                                                           

Summit Grid Reference (New Position):  SN 30059 35918 & SN 30061 35921 & SN 30070 35947 & SN 30073 35949 & SN 30076 35949 (LIDAR)                                                  

Bwlch Height:  193.9m (LIDAR) 

Bwlch Grid Reference:  SN 30543 35784 (LIDAR) 

Drop:  14.2m (LIDAR) 

 

Myrddyn Phillips (April 2025)