Saturday 18 February 2017

Mapping Mountains – Hill Reclassifications – Y Trechol – The Dominant Hills of Wales


Coed Bodlondeb (SH 779 781) - Dominant addition

There has been an addition to the listing of Y Trechol – The Dominant Hills of Wales due to detail included on the Ordnance Survey enlarged mapping hosted on the Geograph website.  This has resulted in the hill being added to the Dominant list.  With the criteria for inclusion to this list being those Welsh P30 hills whose prominence equal or exceed half that of their absolute height.

The details relating to this hill’s inclusion as a Dominant hill are retrospective as it appeared in the Carneddau group of hills when published on Mapping Mountains on the 17th December 2015.

Prior to this hill’s inclusion as a Dominant hill it was listed with an estimated c 27m of drop based on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps giving the hill an uppermost 50m ring contour and bwlch contouring between 20m – 30m, resulting in an estimated summit height of c 53m and an estimated bwlch height of c 26m.

The hill is in the Carneddau group of hills and is placed in the Region of North Wales (Region A, Sub-Region A1) and is situated on the outskirts of Conwy with the Afon Conwy to its immediate north and east.

If wanting to visit the hill it can be accessed relatively easily with public parking available next to where the Offices are marked to the south of the summit on Ordnance Survey maps.  There are a number of paths marked on the map that head up to, or contour around the summit, and as the name of the hill suggests it is part of a wood which consists of deciduous trees.

The name of the hill is Coed Bodlondeb and it is included as a Dominant hill as the Ordnance Survey enlarged map hosted on the Geograph website has contours at 5m intervals giving the hill an uppermost contour of 55m and bwlch contouring between 20m – 25m.  Therefore the summit is estimated as being c 57m high and the bwlch estimated as being c 23m high, with these values giving this hill c 34m of drop and 59.65% Dominance.

Since this hill was originally included in the Y Trechol - The Dominant Hills of Wales list the summit has been surveyed with the Trimble GeoXH 6000 and the bwlch of the hill has been analysed via LIDAR and the resulting values are given below.


The full details for the hill are:


Cardinal Hill:  Tal y Fan

Name:  Coed Bodlondeb

OS 1:50,000 map:  115

Summit Height:  55.6m (converted to OSGM15)

Summit Grid Reference:  SH 77921 78114

Drop Summit to Bwlch:  32.6m (Trimble summit and LIDAR bwlch)

Drop Bwlch to ODN:  22.9m (LIDAR) 

Bwlch Grid Reference:  SH 77852 77725 (LIDAR)

Dominance:  58.70%


Gathering data at the summit of Coed Bodlondeb

For details on the summit survey of Coed Bodlondeb

Myrddyn Phillips (February 2017)



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