Mapping Mountains – Significant Name Changes – 100m Twmpau

Twyn y Cryn (SO 325 008)

There has been a Significant Name Change to a hill that is listed in the 100m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Twyn y Cryn (SO 325 008)

The criteria for the list that this name change applies to are:

100m Twmpau - Welsh hills at or above 100m and below 200m in height with 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 100m and below 200m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The hill 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 above the A4042 road to the west and the A472 road to the north, and has the town of Pont-y-pŵl (Pontypool) towards its west and Brynbuga (Usk) towards its east.

The hill originally appeared in the 100m P30 list on Geoff Crowder’s v-g.me website under a transposed and also partly invented and transposed name of Maes-mawr / Pen Twyn y Cryn, with an accompanying note stating; Names from buildings to the South-West and wood to the North-West.  With these two names relating to what was considered the twin topped nature of this hill.

Maes-mawr / Pen Twyn y Cryn

140c

SO325005

171

152

Names from buildings to the South West & wood to the North-West.

During my early hill listing I thought it appropriate to either invent a name for a hill, or use a name that appeared near to the summit of the hill on Ordnance Survey maps of the day.  My preference was to use farm names and put Pen, Bryn or Moel in front of them or as in this instance transpose the name of a farm and also that of a wood and prefix the latter with the word Pen.  This is not a practice that I now advocate as with time and inclination place-name data can be improved either by asking local people or by examining historic documents, through this form of research an appropriate name for the hill can usually be found.

Extract from the Ordnance Survey 1:25,000 Explorer map

The summit of this hill has now been confirmed as that adjoined to Twyn y Cryn, and as this name is recorded on contemporary Ordnance Survey 1:25,000 Explorer maps and is appropriate for that of the hill there is no reason why it should be prefixed with an invented word.

Therefore, the name this hill is now listed by in the 100m Twmpau is Twyn y Cryn, and this was derived from contemporary Ordnance Survey 1:25,000 Explorer maps.

The full details for the hill are:

Group:  Cymoedd Gwent

Name:  Twyn y Cryn

Previously Listed Name:  Maes-mawr / Pen Twyn y Cryn 

OS 1:50,000 map:  171

Summit Height:  148.1m (LIDAR)

Summit Grid Reference:  SO 32563 00887 (LIDAR)

Bwlch Height:  112.9m (LIDAR)

Bwlch Grid Reference:  SO 32391 01152 (LIDAR) 

Drop:  35.3m (LIDAR)

Myrddyn Phillips (September 2019)