Mapping Mountains – Hill Reclassifications – Y Pedwarau – The 400m Hills of Wales

Crin Fynydd (SO 178 605) – Pedwar reclassified to 400m Sub-Pedwar

There has been a reclassification to the listing of the Y Pedwarau – The 400m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail produced by Joe Nuttall in his surface analysis progamme, with subsequent LIDAR analysis conducted by the DoBIH team and independently by Aled Williams and Myrddyn Phillips. 

Crin Fynydd (SO 178 605)

The criteria for the list that this reclassification applies to are:

Y Pedwarau – The 400m Hills of Wales.  Welsh hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being reclassified to the 400m Sub-Pedwar category.  The criteria for this sub category being all Welsh hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is published on Mapping Mountains in Google Doc format.

Y Pedwarau - The 400m Hills of Wales by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Crin Fynydd and it is adjoined to the Fforest Glud group of hills, which are situated in the easterly part of South Wales (Region B, Sub-Region B3), and it is positioned with the A44 road to its south and a minor road to its south-east, and has the village of Maesyfed (New Radnor) towards the east.

When the original 400m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a 468m summit height and a 438m bwlch height, with both heights based on the spot heights that appear on the Ordnance Survey 1:25,000 Explorer map, and this hill was subsequently listed with 30m of drop based on the above values when the 1^st edition of the Y Pedwarau was published by Europeaklist in May 2013. 

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

However, it was not until LIDAR became available that the 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 image of Crin Fynydd (SO 178 605)

Therefore, the reclassification of this hill to 400m Sub-Pedwar status is due to LIDAR analysis, resulting in a 467.3m summit height and a 438.3m bwlch height, with these values giving this hill 29.0m of drop, which is insufficient for it to be classified as a Pedwar. 

 

The full details for the hill are:

Group:  Fforest Glud 

Name:  Crin Fynydd 

OS 1:50,000 map:  148

Summit Height:  467.3m (LIDAR) 

Summit Grid Reference:  SO 17846 60534 & SO 17846 60536 & SO 17853 60534 (LIDAR) 

Bwlch Height:  438.3m (LIDAR) 

Bwlch Grid Reference:  SO 17865 60748 (LIDAR) 

Drop:  29.0m (LIDAR)

 

For the additions, reclassifications and deletions to Y Pedwarau – The 400m Hills of Wales reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:

 

Y Pedwarau

 

Y Pedwarau – 400m Sub-Pedwarau

 

Y Pedwarau – 390m Sub-Pedwarau

 

Y Pedwarau – 390m Double Sub-Pedwarau

 

Myrddyn Phillips and Aled Williams (August 2023)