Mapping Mountains – Summit Relocations – The Welsh P15s

 

Cae Tŷ (SJ 077 107) 

There has been a Summit Relocation to a hill that used to be 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 Tŷ (SJ 077 107)

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 Tŷ, and this was derived from the Tithe map, and it is adjoined to the Esgeiriau Gwynion group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned encircled by minor roads, with the B4382 road farther to its north-east, the A458 road farther to its south-west and the A495 road farther to its south-east and has the town of Llanfair Caereinion towards the south-east.

When the listing that became known as The Welsh P15s was being compiled, this hill was included in the P14 sub list with an estimated c 14m of drop, based on the 208m summit spot height positioned at SJ 07800 10746 that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and an estimated c 194m 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 summit image of Cae Tŷ (SJ 077 107)

LIDAR analysis gives the highest ground on this hill as 209.7m positioned at SJ 07785 10758.  However, this is to the top of a mound of discarded rocks that is now overgrown, as evidenced by the Google Maps photo below, and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill. 

Photo:  Google Maps

The height produced by LIDAR analysis to the natural summit of this hill is 208.5m and is positioned at SJ 07741 10751, 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 208.5m and is positioned at SJ 07741 10751, 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 44 metres eastward from where the high point of the man-made mound and spot height is positioned. 

 

The full details for the hill are: 

Group:  Esgeiriau Gwynion 

Name:  Cae Tŷ 

OS 1:50,000 map:  125

Summit Height:  208.5m (LIDAR)                                                           

Summit Grid Reference (New Position):  SJ 07741 10751 (LIDAR)                                                  

Bwlch Height:  196.7m (LIDAR) 

Bwlch Grid Reference:  SJ 07212 10935 (LIDAR) 

Drop:  11.8m (LIDAR) 

 

Myrddyn Phillips (May 2025)