Mapping Mountains – Hill Reclassifications – Y Trichant – The 300m Hills of Wales

 

Hafoty Glan y Bala (SH 587 610) – Sub-Trichant addition

There has been an addition to the list of Y Trichant – The 300m Hills of Wales, 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 Hafoty Glan y Bala (SH 587 610)

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

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Hafoty Glan y Bala, and this was derived from the Tithe map, and it is adjoined to the Glyder Fawr group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with minor roads to its north-west and east, the A4086 road to its south-west, and has the village of Llanberis towards the south-west.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was not included in the accompanying Hills to be surveyed sub list, as with a 313m summit spot height on the contemporary Ordnance Survey 1:25,000 Explorer map and with no significant bwlch contours of note it was difficult to know whether any hill of note existed.

Current online Ordnance Survey mapping now shows bwlch contouring between 285m – 290m, with interpolation placing the height at an estimated c 289m and when coupled with the 313m summit spot height, these values give this hill an estimated c 24m of drop. 

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.

Therefore, the addition of this hill to Sub-Trichant status is due to LIDAR analysis, resulting in a 313.2m summit height and a 288.2m bwlch height, with these values giving this hill 25.0m of drop, which is sufficient for it to be classified as a Sub-Trichant. 

 

The full details for the hill are: 

Group:  Glyder Fawr 

Name:  Hafoty Glan y Bala 

OS 1:50,000 map:  114, 115

Summit Height:  313.2m (LIDAR)                                                           

Summit Grid Reference:  SH 58760 61016 (LIDAR) 

Bwlch Height:  288.2m (LIDAR) 

Bwlch Grid Reference:  SH 58906 60906 (LIDAR) 

Drop:  25.0m (LIDAR) 

 

Myrddyn Phillips (June 2025)