Mapping Mountains – Summit Relocations – The Welsh P15s

Cae Pant (SN 908 472) 

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 Pant (SN 908 472)

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 Pant, 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 the South Wales Region (Region B, Sub-Region B1), and it is positioned with minor roads to its north-east and south, and the A483 road to its north-west, and has the town of Llanwrtyd towards the 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 16m of drop, based on the 214m summit spot height that is positioned at SN 90855 47214 and which appears on the Ordnance Survey 1:25,000 Explorer map, and an estimated c 198m bwlch height based on interpolation of 10m contouring between 190m – 200m. 

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 215.2m positioned at SN 90818 47253.  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 Pant (SN 908 472)

The height produced by LIDAR analysis to the natural summit of this hill is 214.5m and is positioned at SN 90813 47233, 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 214.5m and is positioned at SN 90813 47233, 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 42 metres north-westward from where the 214m spot height is positioned and 20 metres southward from the high point of the raised field boundary. 

 

The full details for the hill are: 

Group:  Drygarn Fawr 

Name:  Cae Pant 

OS 1:50,000 map:  147

Summit Height:  214.5m (LIDAR)                                                           

Summit Grid Reference (New Position):  SN 90813 47233 (LIDAR)                                                  

Bwlch Height:  199.2m (LIDAR) 

Bwlch Grid Reference:  SN 90117 47253 (LIDAR) 

Drop:  15.3m (LIDAR) 

 

Myrddyn Phillips (March 2025)