Mapping Mountains – Significant Name Changes – 800m Twmpau

800m Twmpau – Significant Name Changes

The 800m Twmpau (thirty welsh metre prominences and upward) are the Welsh hills at or above 800m and below 900m in height that have a minimum drop of 30m.  Accompanying the main P30 list is a sub list entitled the 800m Sub-Twmpau with the qualification to this sub category being all Welsh hills at or above 800m and below 900m in height with 20m or more and below 30m of drop.

The list is authored by Myrddyn Phillips and the posts that have appeared on Mapping Mountains detailing the significant name changes to the main P30 list and the sub list appear below presented chronologically in receding order.

Mapping Mountains - Significant Name Changes - 800m Twmpau

Craig Berwyn (SJ 071 323) - 1st significant name change

Summit survey post for Craig Berwyn

Bwlch survey post for Craig Berwyn

There has been a Significant Name Change to a hill that appears in the following lists; Y Pellennig, Yr Uchafion, 800m Twmpau and Y Trechol - The Dominant Hills of Wales, with the following details relating to a hill whose summit was surveyed with the Trimble GeoXH 6000 on the 21^st June 2014 and its bwlch on the 13th September 2019.

The criteria for the four listings that this name change affects are:

Y Pellennig –The Remotest Hills of Wales comprise all Welsh hills whose summit is 2.5km or more from the nearest paved public road and which have a minimum 15m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams.

Yr Uchafion - All Welsh hills at or above 500m in height that have 15m minimum drop.  The list is co-authored by Myrddyn Phillips and Aled Williams. 

800m Twmpau - All Welsh hills at or above 800m and below 900m in height with 30m minimum drop.  The list is authored by Myrddyn Phillips.  

Y Trechol - The Dominant Hills of Wales - These are the Welsh P30 hills whose prominence  equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those addition Welsh P30 hills whose prominence is 33% or more and below 50% of their absolute height.

The hill is situated in the Y Berwyn, which is an extensive group of hills positioned in the south-eastern part of north Wales, and is relatively remote for a Welsh hill with the nearest towns being Llandrillo to the north-west and Llanarmon Dyffryn Ceiriog to the east.

The Trimble GeoXH 6000 gathering data at the summit of Craig Berwyn (SJ 071 323) with the trig pillar atop Cadair Berwyn (SJ 072 327) in the background on the left

The hill first made an appearance in a hill list as Cader Berwyn, S. Top in a 1929 update to the Twenty-Fives which was compiled by John Rooke Corbett and published by the Rucksack Club Journal.  Since this time the hill has been listed a number of times and usually by names associated with that of Cadair Berwyn, which strictly speaking is the hill to its north positioned at SJ 072 327, and which has a triangulation pillar situated at its summit and a map height of 827m.

Unfortunately all previous hill list authors have used the map name that appears nearest to the summit of this hill, although doing this is convenient it has conjured up all manner of  combinations of inappropriate names centred around that of its adjacent hill, these names include; Cadair Berwyn New Top, Cadair Berwyn South Top as well as the use of the adjacent hill’s name; Cadair Berwyn.

The hill was only confirmed by the Ordnance Survey as the highest in the Y Berwyn when contacted by Bernard Wright who had recognised that the summit of the hill was higher than its adjacent northerly peak; Cadair Berwyn, and also higher than its adjacent southerly peak; Moel Sych, Bernard suggested the name of Craig Uchaf for this hill as it seemingly had no name for it on the map of the day.  This is the name previously given the hill in unpublished format within the Yr Uchafion prior to extensive place-name research for this area taking place.

As a result of this research the hill has subsequently appeared under the name of Craig Berwyn in all four of the previously mentioned lists, this is the name that some local farmers and shepherds know the hill by, ironically this name already appears on Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps.

The full details for the hill are:

Group:  Y Berwyn

Name:  Craig Berwyn

Previously Listed Name:  Craig Uchaf 

Summit Height:  832.0m (converted to OSGM15)

OS 1:50,000 map:  125

Summit Grid Reference:  SJ 07163 32351 

Drop:  347.3m

Dominance:  41.74%

For details on the summit survey of Craig Berwyn

Myrddyn Phillips (July 2016)