Mapping Mountains – Significant Name Changes – The Welsh P15s

Gamallt (SN 968 714) 

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 Gamallt (SN 968 714)

The criteria for the list that this name change applies 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 Hirddywel group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B2), and it is positioned with minor roads to its north, west and east, and the A470 road farther to its west, and has the town of Rhaeadr Gwy (Rhayader) towards the south.

When the listing that became known as The Welsh P15s was being compiled, this hill was included in the main list under the point (Pt. 398m) notation with 15m of drop, based on the 398m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 383m 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. 

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 Tithe maps 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.  However, in this instance it is the Tithe map that names the extended land where the summit of this hill is situated as a part of the land known as Gamallt.

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

 

The full details for the hill are: 

Group:  Hirddywel 

Name:  Gamallt 

Previously Listed Name:  Pt. 398m 

OS 1:50,000 map:  136, 147

Summit Height:  397.4m (LIDAR)                                                           

Summit Grid Reference:  SN 96811 71472 (LIDAR)                                                  

Bwlch Height:  383.5m (LIDAR) 

Bwlch Grid Reference:  SN 96756 71262 (LIDAR) 

Drop:  13.9m (LIDAR)

 

Myrddyn Phillips (October 2025)