Mapping Mountains – Significant Name Changes – 200m Twmpau

 

Henllan Uchaf (SN 770 983) 

There has been a Significant Name Change to a hill that is listed in the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Henllan Uchaf (SN 770 983)

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 that have 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.  The list is authored by Myrddyn Phillips, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

200m Twmpau by Myrddyn Phillips

The hill is adjoined to the Banc Llechwedd Mawr group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B1), and it is positioned enclosed by minor roads, with the A489 road farther to its north and the A487 road farther to its west, and has the town of Machynlleth towards the north-west.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list under the transposed name of Pen-y-rhiw, which is a prominent name that appears adjacent to this hill on the Ordnance Survey 1:25,000 Explorer map.

Pen-y-rhiw

202m

SN770983

135

23/215

During my early hill listing I thought it appropriate to either invent a name for a hill or use a name that appeared near to the summit of the hill on Ordnance Survey maps of the day, with little consideration for the meaning of the name and where it was appropriately applied to.  My preference was to use farm names and put Pen, Bryn or Moel in front of them or as in this instance transpose the name of what I presumed referred to the hill, and in fact is a farm name, and use it for that of the hill.  This is not a practice that I now advocate as with time and inclination place-name data can be improved either by asking local people or by examining historic documents, through this form of research an appropriate name for the hill can usually be found. 

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 205 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 a part of Henllan Fawr farm in the apportionments, with the details on the Tithe map appearing in the parish named as Machynlleth 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 Henllan Fawr, and this was derived from the Tithe map. 

 

The full details for the hill are:

Group:  Banc Llechwedd Mawr

Name:  Henllan Fawr

Previously Listed Name:  Pen-y-rhiw   

OS 1:50,000 map:  135

Summit Height:  201.4m (LIDAR) 

Summit Grid Reference:  SN 77002 98312 (LIDAR) 

Bwlch Height:  160.7m (LIDAR) 

Bwlch Grid Reference:  SN 77818 98286 (LIDAR) 

Drop:  40.7m (LIDAR) 

 

Myrddyn Phillips (April 2025)