Caer Helen (SH 325 780) – Welsh P15 addition
There has been an addition 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 Caer Helen (SH 325 780) |
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 |
When the listing that became known as The Welsh P15s was being compiled, this hill was not included in either the main P15 list or the accompanying P14 sub list, but it was documented with an estimated c 13m of drop, based on the 34m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 21m bwlch height, based on interpolation of 5m contouring between 20m – 25m.
Extract from the Ordnance Survey 1:25,000 Explorer map |
Therefore, the addition of this hill to Welsh P15 status is due to LIDAR analysis, resulting in a 33.9m summit height and a 17.4m bwlch height, with these values giving this hill 16.5m of drop, which is sufficient for it to be included in the main list of The Welsh P15s.
The full details for the hill are:
Group: Ynys Môn
Name: Caer Helen
OS 1:50,000 map: 114
Summit Height: 33.9m (LIDAR)
Summit Grid Reference: SH 32589 78052 (LIDAR)
Bwlch Height: 17.4m (LIDAR)
Bwlch Grid Reference: SH 32770 78215 (LIDAR)
Drop: 16.5m (LIDAR)
Myrddyn Phillips
(October 2021)
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