Cae Bryn Celli Wen (SH
513 701)
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 Bryn Celli Wen (SH 513 701) |
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 listed by is Cae
Bryn Celli Wen and this was derived from the Tithe map, and it is adjoined to the Ynys Môn group of hills, which are situated in the north-western part of
North Wales (Region A, Sub-Region A1), and it is positioned with the A5 and A55
roads to its north, minor roads to its north-west and south-west and the A4080
road to its east, and has the village of Llanfair Pwllgwyngyll towards the north-east.
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 17m of drop, based
on an estimated c 51m summit height positioned at SH 51467 70268 and a 34m
bwlch height based on the spot height that appears on the Ordnance Survey 1:50,000
Landranger and 1:25,000 Explorer 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 summit image of Cae Bryn Celli Wen |
The summit height produced by LIDAR analysis is 51.3m
and is positioned at SH 51314 70143, 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
hill’s high point is found to be positioned; in a different field, to a
different feature such as in a conifer plantation, placed within a different
map contour, to a different point where a number of potential summit positions
are within close proximity, or 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 that is judged to be 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 51.3m and this is positioned at SH 51314 70143, this position is not
given a spot height on contemporary Ordnance Survey 1:50,000 Landranger and
1:25,000 Explorer maps, and is approximately 150 metres south-westward from
where the previously listed summit is positioned.
The full details for the
hill are:
Group: Ynys
Môn
Name: Cae Bryn Celli Wen
OS 1:50,000 map: 114,
115
Summit Height: 51.3m (LIDAR)
Summit Grid Reference
(New Position): SH 51314 70143 (LIDAR)
Bwlch Height: 33.3m (LIDAR)
Bwlch Grid
Reference: SH 51742 69854 (LIDAR)
Drop: 18.0m (LIDAR)
Myrddyn Phillips (May
2021)
