Mapping Mountains – Significant Name Changes – The Welsh P15s

 

March Mynydd Ucha (SO 097 282) 

There has been a Significant Name Change to a hill that was listed in The Welsh P15s, 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 March Mynydd Ucha (SO 097 282)

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

The Welsh P15s – Welsh hills with 15m minimum drop, irrespective of their height, with an accompanying sub list entitled the Welsh Sub-P15s, with the criteria for this sub category being all Welsh hills with 14m or more and below 15m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list appearing on Mapping Mountains on the 10^th May 2019. 

The Welsh P15s by Myrddyn Phillips

The hill is adjoined to the Mynydd Epynt group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned enclosed by minor roads, with the A470 road farther to its west and the A40 road farther to its south-west, and has the town of Aberhonddu (Brecon) towards the west.

When the listing that became known as The Welsh P15s was being compiled, this hill was listed under the point (Pt. 270m) notation and included in the P14 sub list with an estimated c 14m of drop, based on the 270m summit spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map and an estimated c 256m bwlch height, based on interpolation of 10m contouring between 250m – 260m. 

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

However, it was not until LIDAR became available that the numerical details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR analysis gives the natural summit of this hill as 271.1m and with a 257.4m bwlch height, these values give this hill 13.7m of drop, which is insufficient for it to be classified as a Welsh P15.

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 393 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 March Mynydd Ucha in the apportionments, with the details on the Tithe map appearing in the parish of Llanhamlach and in the county named as Brecon. 

Extract from the apportionments

Therefore, the name this hill is now listed by is March Mynydd Ucha and this was derived from the Tithe map. 

 

The full details for the hill are: 

Group:  Mynydd Epynt 

Name:  March Mynydd Ucha 

Previously Listed Name:  Pt. 270m 

OS 1:50,000 map:  161

Summit Height:  271.1m (LIDAR)                                                           

Summit Grid Reference:  SO 09744 28233 (LIDAR) 

Bwlch Height:  257.4m (LIDAR) 

Bwlch Grid Reference:  SO 09741 28417 (LIDAR) 

Drop:  13.7m (LIDAR) 

 

Myrddyn Phillips (July 2024)