Garth Fawr (SO 082 059)
There has been a Summit Relocation to a hill that
is listed in the Y Pedwarau – The 400m
Hills of Wales, with the summit height and its position derived from
Ordnance Survey Open Data hosted as an interactive map on the WalkLakes
website.
 |
| Garth Fawr (SO 082 059). Photo: Rob Woodall |
The criteria for the list that this summit
relocation applies to are:
Y Pedwarau – The 400m Hills of Wales.
Welsh hills at or above 400m and below 500m in height that have 30m
minimum drop, the list is co-authored by Myrddyn Phillips and Aled Williams and
is published on Mapping Mountains in Google Doc format.
The name the hill is listed by is Garth Fawr and it
is a relatively recent man-made construction and is the result of waste spoil from
the Ffos-y-fran opencast mine that is now considered solid and stable. Therefore, it does not possess any separate
ring contours for the area of its summit on either the Ordnance Survey 1:50,000
Landranger or the 1:25,000 Explorer map.
 |
| Extract from the Ordnance Survey 1:25,000 Explorer map |
Garth Fawr is adjoined to the Cymoedd Gwent group of hills, which are situated in the eastern part of
South Wales (Region C, Sub-Region C2), and
it is positioned with the A4060 road to its west and the A469 road to its east,
and has the town of Merthyr Tudful towards the north-west.
When this hill was
included in the list of Y Pedwarau- The 400m Hills of Wales published on Mapping Mountains, the summit
position was given as the following ten figure grid reference of SO 08597 05972,
based on interpolation of one of three uppermost 410m ring contours that used
to appear on the OS Maps website.
Another resource now available online is the
WalkLakes website which hosts an interactive map originated from the Ordnance
Survey Open Data programme. This map has
many spot heights not on other publicly available maps and shows a 410m spot height
on the summit area of this hill.
 |
| Extract from the WalkLakes website |
The position of the 410m spot height comes within the
parameters of the Summit Relocations used within this page heading, these
parameters are:
The term Summit Relocations applies to any listed
hill whose summit meets the following criteria; where there are a number of
potential summit positions within close proximity and the highest point is not
where previously given, 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, or when the summit of the hill is
in a different field compared to where previously given, or when it is
positioned to a different feature such as in a conifer plantation, or when the
high point of the hill is placed within a different map contour compared to its
previous listed position, 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.
Therefore, the new summit
height for this hill is 410m and is positioned at SO 08260 05940 and appears as
a spot height on the interactive map hosted on the WalkLakes website which is
produced from the Ordnance Survey Open Data programme, 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 350 metres westward from where the
previously listed summit is positioned.
The full details for the hill are:
Group: Cymoedd Gwent
Name: Garth Fawr
OS 1:50,000 map: 160
Summit Height: 410m (spot
height)
Summit Grid Reference (new position): SO 08260 05940 (spot height)
Bwlch Height: c 375m (interpolation)
Bwlch Grid Reference:
SO 08676 06119 (interpolation)
Drop: c 35m (spot
height summit and interpolated bwlch)
Aled Williams and Myrddyn Phillips (April 2020)
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