Mapping Mountains – Significant Name Changes – 200m Twmpau

Henfaes Common (SO 120 974) 

There has been a Significant Name Change to a hill that was listed in the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Henfaes Common (SO 120 974)

The criteria for the list that this name change applies to are: 

200m Twmpau - 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, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The hill is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is positioned with the B4390 road to its north, the B4389 road to its south and the A483 road to its east, and has the village of Betws Cedewain towards the south. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was not included in the accompanying Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed under the point (Pt. 214m) notation with 20m of drop, based on the 214m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map, and the 194m bwlch spot height that appeared on the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

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

As the summit of this hill comprises bounded land the details for it were examined on the Tithe map.  The term Tithe map is generally given to a map of a Welsh or English parish or township and which was prepared after the 1836 Tithe Commutation Act.  This act allowed tithes to be paid in cash rather than goods.  The Tithe maps gave names of owners and occupiers of land in each parish and importantly for place-name research they also included the name of enclosed land.  This enclosed land is usually based on a field system, however not every field is given a name, but many are and especially so in Wales. 

Extract from the Tithe map

The enclosed land where the summit of this hill is situated is given the number B 78 on the Tithe map, this can be cross referenced against the apportionments; it is these apportionments that give the name of the owner or occupier of the land as well as the name of the land.  The land where the summit of this hill is situated is named as Wood in Henfaes Common, with the details on the Tithe map appearing in the parish of Bettws and in the county named as Montgomery. 

Extract from the apportionments

Therefore, the name this hill is now listed by in the 200m Twmpau is Henfaes Common, and this was derived from the Tithe map. 

 

The full details for the hill are:

Group:  Carnedd Wen

Name:  Henfaes Common

Previously Listed Name:  Pt. 214m   

OS 1:50,000 map:  137

Summit Height:  215.2m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SO 12003 97409 (Trimble GeoXH 6000) 

Bwlch Height:  198.8m (LIDAR) 

Bwlch Grid Reference:  SO 12171 97587 (LIDAR) 

Drop:  16.4m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (February 2021)