Mapping Mountains – Significant Name Changes – 100m Twmpau

 

Pt. 170.7m (SJ 193 018) 

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 and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Pt. 170.7m (SJ 193 018)

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 100m Twmpau by Myrddyn Phillips

The hill is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is positioned with a minor road to its north, the B4385 road to its west, the B4390 road to its south and the A483 road to its east, and has the village of Aberriw (Berriew) towards the south-west. 

When the original 100m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was listed under the transposed name of Allt Upper, which is a prominent name that appears near the summit of this hill on the contemporary Ordnance Survey 1:25,000 Explorer map.

Allt Upper

169m

SJ193018

136

216

Included by contour configuration

 

During my early hill listing I paid little regard to name placement on the map, or the meaning of names and to what feature the name was appropriately applied to.  Therefore, I prioritised names for listing purposes that I now understand are either inappropriate or where another name is viewed as being more appropriate, with the previously listed name of Allt Upper applying to a district and not necessarily to the hill itself. 

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

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.  However, occasionally even when research is conducted an appropriate name for the hill may not be found, and on such occasions the listing protocol is to use the point (Pt. 170.7m) notation, and for this hill, this is such an example. 

Therefore, the name this hill is now listed by in the 100m Twmpau is Pt. 170.7m, and this is being used as the author has not found an appropriate name for it either through historic research and / or local enquiry. 

 

The full details for the hill are: 

Group:  Carnedd Wen 

Name:  Pt. 170.7m

Previously Listed Name:  Allt Upper 

OS 1:50,000 map:  136

Summit Height:  170.7m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SJ 19323 01898 (Trimble GeoXH 6000)

Bwlch Height:  132.5m (LIDAR)

Bwlch Grid Reference:  SJ 18115 01656 (LIDAR)

Drop:  38.2m (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

Myrddyn Phillips (June 2021)