Pen Twyn (SN 857 463)
This is the thirty seventh post under the heading of Significant Name Changes, and the following details are in respect of a hill that was surveyed with the Trimble GeoXH 6000 on the 25th September 2015.
The hill is part of the Elenydd, which forms one of the largest groups of hills in the country and which is situated in the central part of mid and west Wales. The hill is on the south-eastern periphery of this hill group and is positioned above the small town of Llanwrtyd (Llanwrtyd Wells) to its east.
|The Trimble GeoXH 6000 gathering data at the summit of Pen Twyn|
The hill appeared in the 400m P30 list on Geoff Crowder’s v-g.me website under the name of Pen Garn-gou, which is a name that appeared close to the summit of the hill on Ordnance Survey 1:25,000 Explorer maps of the day. This listing of hills is now co-authored with Aled Williams and known as Y Pedwarau.
During my early hill listing I paid little regard to name placement on a 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 inappropriate, and Pen Garn-gou is such an example as this name has been consistently applied by the Ordnance Survey to land that is below and to the south of this hill’s summit, whilst the larger scale Ordnance Survey Six-Inch map is consistent in applying the name Pen Twyn to the land where the summit of the hill is situated.
Since publication of these P30 lists on Geoff Crowder’s v-g.me website there have been a number of Ordnance Survey maps made available online, some of these are historical such as the series of Six-Inch maps on the National Library of Scotland website, whilst others are current and digitally updated such as the enlarged map on the Geograph website. One of the historical maps now available is the Ordnance Survey One-Inch ‘Old Series’ map which was the first map made publicly available by the Ordnance Survey, and it is details on this map that formed the basis for the change in this hill’s listed name.
|Extract from the Ordnance Survey One-Inch 'Old Series' map|
The name this hill is now listed by in Y Pedwarau (Europeaklist May 2013 and Haroldstreet January 2014) is Pen Twyn and this was derived from the Ordnance Survey One-Inch ‘Old Series’ map and later confirmed by the series of Ordnance Survey Six-Inch maps.
|Extract from the series of Ordnance Survey Six-Inch maps|
The full details for the hill are:
Name: Pen Twyn
Previously Listed Name: Pen Garn-gou
Summit Height: 476.6m (converted to OSGM15)
OS 1:50,000 map: 147
Summit Grid Reference: SN 85798 46301
Myrddyn Phillips and Aled Williams (September 2016)