Mapping Mountains – Hill Reclassifications – 200m Twmpau

Dinas Mawr (SH 808 539) – 200m Sub-Twmpau reclassified to 200m Twmpau

There has been a confirmation of a reclassification to the 200m Twmpau (thirty welsh metre prominences and upward) ranks of hills due to a survey with the Trimble GeoXH 6000, with these details being retrospective as the survey that confirmed this reclassification was conducted on the 24^th December 2013.

The criteria for 200m Twmpau status is all Welsh hills at or above 200m and below 300m in height with 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop. 

This hill was listed in the Hills to be surveyed sub list accompanying the original Welsh P30 lists on Geoff Crowder’s v-g.me website and was only reclassified to P30 status when the sub list was standardised and interpolated drop values were accepted for qualification to the main P30 list.

Prior to the survey with the Trimble GeoXH 6000 the hill was listed with 33m of drop based on the 254m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 221m bwlch spot height that appears on the Ordnance Survey enlarged mapping hosted on the Geograph website.

The name of the hill is Dinas Mawr and it  is situated in the Mynydd Hiraethog range with its Cardinal Hill being Mwdwl Eithin (SH 917 540) and is positioned immediately above the A5 road which is to its south, and is placed between the small communities of Capel Garmon to the north north-east and Penmachno to the south south-west.

The upper section of the hill is a part of designated open access land and this can be accessed from public footpaths originating from the A5 road south-west of the summit or from a minor lane to the east of the summit.

The full details for the hill are:

Cardinal Hill:  Mwdwl Eithin

Summit Height:  254.0m (converted to OSGM15)

Name:  Dinas Mawr

OS 1:50,000 map:  116

Summit Grid Reference:  SH 80884 53931

Drop:  33.9m (converted to OSGM15)

Dinas Mawr (SH 808 539) this hill's reclassification to 200m Twmpau status is now confirmed by a survey with the Trimble GeoXH 6000

For details on the survey that confirmed the reclassification of this hill to 200m Twmpau status

Myrddyn Phillips (August 2017)