Mapping Mountains – Summit Relocations – The Fours – The 400m Hills of England

Fron Hill (SO 224 835) 

There has been a Summit Relocation to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis initially conducted by Aled Williams and subsequently by Myrddyn Phillips. 

LIDAR image of Fron Hill (SO 224 835)

The criteria for the list that this summit relocation applies to are:

The Fours – The 400m Hills of England.  English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English 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 the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Fron Hill and this was derived from the Ordnance Survey Draft Surveyors map, and it is adjoined to the Cilfaesty group of hills, which are situated in the county of Shropshire close to the Welsh border, and it is positioned with minor roads to its north-east and north-west, and the B4368 road to its south-west, and has the town of Clun towards the east south-east.

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed with an estimated c 21m of drop, based on the 413m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and which is positioned at SO 22202 83519, and an estimated c 392m col height, based on interpolation of 5m contouring between 390m – 395m. 

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.

Initial LIDAR analysis gave the highest ground on this hill as 412.6m positioned at SO 22201 83532, and it was this position that was given for the summit of this hill when the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018. 

LIDAR summit image of Fron Hill (SO 224 835) 

Analysis of the latest LIDAR that is now available gives the highest ground on this hill as 413.0m positioned at SO 22428 83599.  LIDAR indicates this to be a mound with a tree on it.  There is no map evidence of this being ancient in original and therefore the mound could be a relatively recent man-made construct, but until this is proven it is this position that is now being given for the summit of this hill, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to when the high point is positioned in a different field, to a different feature such as a conifer plantation, within a different map contour, a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 413.0m and this is positioned at SO 22428 83599.  This position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is approximately 225 metres east north-eastward from where the previously listed summit was positioned.

 

The full details for the hill are:

Group:  Cilfaesty

Name:  Fron Hill

OS 1:50,000 map:  137

Summit Height:  413.0m (LIDAR)

Summit Grid Reference (New Position):  SO 22428 83599 (LIDAR)

Col Height:  391.7m (LIDAR)

Col Grid Reference:  SO 22050 84209 (LIDAR)

Drop:  21.3m (LIDAR)

 

Myrddyn Phillips and Aled Williams (November 2023)