Mapping Mountains – Significant Name Changes – 100m Twmpau

 

Tŷ Canol (SH 471 907) 

There has been a Significant Name Change to a hill that is listed in the 100m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data. 

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

100m Twmpau - Welsh hills at or above 100m and below 200m in height with 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 100m and below 200m 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 100m Twmpau by Myrddyn Phillips

The hill is adjoined to the Ynys Môn group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is encircled by minor roads with the A5025 road farther to its west, and has the village of Pen-y-sarn towards the west south-west. 

When the original 100m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category. 

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

After 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. 165m) notation and it was listed with 21m of drop, based on the 165m summit spot height and the 144m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.  With the 166m summit spot height that appears on the interactive mapping on the Magic Maps website is now being prioritised. 

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 172 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 Tŷ Canol in the apportionments, with the details on the Tithe map appearing in the parish of Llaneilian and in the county named as Anglesey. 

Extract from the apportionments

Therefore, the name this hill is now listed by in the 100m Twmpau is Tŷ Canol, and this was derived from the Tithe map.

 

The full details for the hill are: 

Group:  Ynys Môn 

Name:  Tŷ Canol

Previously Listed Name:  Pt. 165m 

OS 1:50,000 map:  114

Summit Height:  166m (spot height) 

Summit Grid Reference:  SH 47141 90737 (spot height) 

Bwlch Height:  144m (spot height) 

Bwlch Grid Reference:  SH 47087 91141 (spot height) 

Drop:  22m (spot height summit and bwlch) 

 

Myrddyn Phillips (March 2021)