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

Significant Height Revisions post for Craig Berwyn

There has been a Significant Name Change to a hill that is listed in the Y Pellennig – The Remotest Hills of Wales, The Welsh Highlands – Uchafion Cymru, 800m Twmpau and Y Trechol - The Dominant 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.

Craig Berwyn (SJ 071 323)

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

Y Pellennig –The Remotest Hills of Wales - Welsh hills whose summit is at least 2.5km from the nearest paved public road and the hill has a minimum 15m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available as a downloadable e-booklet or print-booklet version on Mapping Mountains Publications with the up-to-date master list available on Mapping Mountains to download in Google Doc format. 

Y Pellennig - The Remotest Hills of Wales by Myrddyn Phillips and Aled Williams

The Welsh Highlands – Uchafion Cymru – Welsh hills at or above 500m in height with 15m minimum drop, with an accompanying sub list entitled the Welsh Highland Subs, the criteria for which is all Welsh hills at or above 500m in height with 10m or more and below 15m of drop.  This list is authored by Myrddyn Phillips and Aled Williams with the Introduction to the list published on Mapping Mountains in November 2015 and the latest update relating to the list published on Mapping Mountains in January 2023.

The Welsh Highlands - Uchafion Cymru by Aled Williams and Myrddyn Phillips

800m Twmpau - Welsh hills at or above 800m and below 900m in height with 30m minimum drop, with an accompanying sub list entitled the 800m Sub-Twmpau with the criteria for 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, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.  The list is authored by Myrddyn Phillips and is available to download in Google Doc format from Mapping Mountains. 

800m Twmpau by Myrddyn Phillips

Y Trechol - The Dominant Hills of Wales - Welsh P30 hills whose prominence  equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015, and the list is now available in its entirety on Mapping Mountains in Google Doc format. 

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

The hill is adjoined to the Craig Berwyn group of hills, which are situated in the eastern part of North Wales (Region A, Sub-Region A2), and it is positioned with the B4401 road to its north-west, the B4391 road to its south-west and minor roads towards its south and east south-east, and has the small communities of Llandrillo towards the north-west and Llanarmon Dyffryn Ceiriog towards the east.

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

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 used for the hill when The Welsh Highlands - Uchafion Cymru was first compiled by Myrddyn Phillips and prior to extensive place-name research for this area taking place.

Therefore, 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 the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

The full details for the hill are:

Group:  Craig Berwyn

Name:  Craig Berwyn

Previously Listed Name:  Craig Uchaf 

OS 1:50,000 map:  125

Summit Height:  832.0m (converted to OSGM15)

Summit Grid Reference:  SJ 07163 32351 

Bwlch Height:  484.7m (converted to OSGM15)

Bwlch Grid Reference:  SJ 01628 30532

Drop:  347.3m

Dominance:  41.74%

Remoteness:  2.825km

Myrddyn Phillips (July 2016)