Mapping Mountains – Significant Name Changes – Y Pedwarau - The 400m Hills of Wales

Pen Crwn (SN 963 736)

There has been a Significant Name Change to a hill that is listed in the Y Pedwarau – The 400m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from a Trimble GeoXH 6000 survey conducted by Myrddyn Phillips.

The Trimble GeoXH 6000 gathering data at the summit of Pen Crwn

The criteria for the list that this name change 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, accompanying the main list are five categories of sub hills; 500m Sub-Pedwarau, 500m Double Sub-Pedwarau, 400m Sub-Pedwarau, 390m Sub-Pedwarau and the 390m Double Sub-Pedwarau.  The list is co-authored by Myrddyn Phillips and Aled Williams and is published on Mapping Mountains in Google Doc format.

Y Pedwarau - The 400m Hills of Wales by Myrddyn Phillips and Aled Williams

The hill is adjoined to the Hirddywel group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B2), and it is positioned with the A470 road to its south-west and the B4518 road to its east, and has the small community of Pant-y-dŵr towards the north-east and the town of Rhaeadr Gwy (Rhayader) towards the south.

The hill appeared in the original Welsh 400m P30 list compiled by Myrddyn Phillips and published on Geoff Crowder’s v-g.me website, under the transposed name of Cefn Lletyhywel, which is a name that appears to the south of its summit on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

Cefn Lletyhywel

487m

SN963736

136/147

214

When Myrddyn Phillips first compiled this list he 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, names were prioritised for listing purposes that are now considered inappropriate, and Cefn Lletyhywel is such an example as this name has been consistently applied by Ordnance Survey to land below and to the south of the summit of this hill, whilst a number of different scaled Ordnance Survey maps position the name Pen Crwn as applicable to land taking in the summit of this hill.  

Extract from the Ordnance Survey series of Six-Inch maps

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

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

Therefore, the name this hill is now listed by in the Y Pedwarau - The 400m Hills of Wales is Pen Crwn and this was derived from a number of different scaled Ordnance Survey maps that place this name applicable to land that takes in the summit of this hill.

The full details for the hill are:

Group:  Hirddywel

Name:  Pen Crwn

Previously Listed Name:  Cefn Lletyhywel 

OS 1:50,000 map:  136, 147

Summit Height:  486.7m (converted to OSGM15)

Summit Grid Reference:  SN 96320 73629

Bwlch Height:  434.7m (converted to OSGM15)

 

Bwlch Grid Reference:  SN 95566 75036

Drop:  52.0m

Myrddyn Phillips and Aled Williams (October 2016)