Cae Cwar y Tŷ (SN 907 499)
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.
%20-%20LIDAR%20hill%202.jpg) |
| LIDAR image of Cae Cwar y Tŷ (SN 907 499) |
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 10th
May 2019.
 |
| The Welsh P15s by Myrddyn Phillips |
The name the hill is now listed by is Cae Cwar y Tŷ, 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 South Wales (Region B, Sub-Region B1), and it
is positioned with the A483 road to its north and a minor road to its
south-west and east, and has the town of Llanwrtyd towards the south-west.
When the listing that became known as The Welsh P15s was being compiled, this
hill was included in the accompanying sub list with 14m of drop, based on the
257m summit spot height positioned at SN 90720 49939 and the 243m bwlch spot
height, both of which appeared on the Ordnance Survey Vector Map Local hosted
on the Geograph website and which was entitled the Interactive Coverage Map.
%20-%201%2025000.jpg) |
| 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 259.1m positioned at SN 90712 49930 and SN 90717 49931. 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.
%20-%20LIDAR%20summit%202.jpg) |
| LIDAR summit image of Cae Cwar y Tŷ (SN 907 499) |
The height produced by LIDAR analysis to the
natural summit of this hill is 259.0m and is positioned at SN 90705 49957, 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 259.0m and
is positioned at SN 90705 49957, 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 18 metres north-westward from where the 257m spot height was
positioned and approximately 26 metres north-westward from the high point of
the raised field boundary.
The full details for the hill are:
Group: Drygarn Fawr
Name: Cae Cwar y Tŷ
OS 1:50,000 map: 147
Summit Height: 259.0m (LIDAR)
Summit Grid Reference (New Position): SN 90705 49957 (LIDAR)
Bwlch Height: 243.4m (LIDAR)
Bwlch Grid Reference: SN 90715 49674 & SN 90716 49675 (LIDAR)
Drop: 15.6m (LIDAR)
Myrddyn Phillips (April
2025)
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