Showing posts with label Gorn Hill. Show all posts
Showing posts with label Gorn Hill. Show all posts

Thursday, 15 January 2026

Mapping Mountains – Trimble Surveys – Hirddywel

 

19.11.25  Gorn Hill (SN 968 844) 

Gorn Hill (SN 968 844)

I’d only visited Gorn Hill once before in January 2003 and a second visit was long overdue, especially as Eryl and I had mentioned this hill for a small walk on a number of occasions over recent years and today with fairly settled weather, albeit with a chilled easterly breeze, proved as good a day as any to meet and venture forth to the Gorn.  We also had the advantage of Rita offering to drop us off at the top of the road which leads to the footpath for the usual ascent of the hill.

A few breeze blown sleety drops of rain skidded across the sky as we started our walk from the top of the road following the lane leading to Gorn Farm.  These were being blown in on an easterly breeze and the hills adjoined to Pegwn Mawr that from our vantage point were now behind us, were adorned with the first snows of winter with their prominent wind turbines marching across their upper ridge. 

Dusting of snow on the Pegwn Mawr hills

There’s a beauty to fields and the patterns they create, even those that are now just greened and not meadowed.  Their boundaries create these patterns across the land, with hedges standing out compared to those that are just fenced.  From where we now were, the foreground of these patch-worked fields all emerald green in low early winter light fed the eye toward distant gently rising hills, some with a dusting of snow crowning their tops.  Overhead a Red Kite majestically played in the breeze, its bronzed colour standing out as flashes of sunlight caught its wing tips.  It felt good to be out. 

Patch-worked fields

The footpath led past Gorn Farm where a small herd of black cattle met us in a field.  They ran this way and that, keeping their distance but always inquisitive.  Flashes of sunlight added depth to the landscape, accentuating the smooth curved contours of near fields, with snow-capped hills adding perspective of height to the scene.  Away to our north the pyramidal profile of Moel y Golfa and the Breiddin stood out on the horizon, with green fields and speckled patches of white sheep as foreground.  Even relatively low heighted hills can give excellent views and especially so in winter light. 

The distant Breiddin on the right

From this approach it’s an easy route to the summit of Gorn Hill with good signposting and gates indicating the way.  The high point is close to the public footpath, and easy to reach.  The summit has two options vying for high point, with LIDAR confirming the highest.  For me this was another day without taking summit data with the Trimble, which is becoming the norm, this is partly due to the inordinate amount of time that even one data set can incur and having previously LIDARed the hill, this would suffice for its numerical data. 

Eryl heading toward the summit of Gorn Hill

I soon joined Eryl on the summit having used the Trimble as a hand-help GPS device to indicate what field the summit was in and then what out of the two options the high point of the hill was.  We stayed on top for a while, taking a number of photos and chatting.  It was good to be out on a hill with Eryl, something that has been neglected for a number of years. 

The summit of Gorn Hill

From the summit we backtracked to the gate that had given us access into the high field and joined up with the public footpath heading down the hill toward the easterly realms of Llanidloes.  Our continued route down was now on a steepening field and as we lost height the town was edged in sunlight nestled in its low lying plain and formed a perfect foreground with distant snow-capped hills beyond. 

Looking down on Llanidloes

We stopped on a number of occasions on our decent, and chatted about all manner of things, many of times now gone and those distant hills never to be visited again.  This is one of the customs of increasing age where memory fulfills what was once expectation.

Our route took us onto the Gorn Lane and from here it was only a left turn and a minute or so’s walk to where Eryl and Rita live.  A cup of tea and delicious meal was soon on the table; a perfect end to a very fulfilling couple of hours on the hill. 

   

Survey Result: 

 

Gorn Hill 

Summit Height:  326.4m (LIDAR)  

Summit Grid Reference:  SN 96895 84496 (LIDAR) (summit relocation)

Bwlch Height:  278.1m (LIDAR)

Bwlch Grid Reference:  SN 97747 83851 & SN 97747 83848 (LIDAR) 

Drop:  48.3m (LIDAR)

Dominance:  14.80% (LIDAR)

 

 

For further details please consult the Trimble Survey Spreadsheet

Wednesday, 20 November 2024

Mapping Mountains – Summit Relocations – Y Trichant – The 300m Hills of Wales

 

Gorn Hill (SN 968 844) 

There has been a Summit Relocation to a hill that is listed in the 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 Gorn Hill (SN 968 844)

The criteria for the list that this summit relocation 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 13th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1st January 2022. 

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

The name the hill is listed by is Gorn Hill, and it 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 the A470 road to its north and a minor road to its south, and has the town of Llanidloes towards the west.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a 326m summit height, based on the spot height positioned at SN 96892 84574 that appears on the contemporary Ordnance Survey 1:25,000 Explorer map. 

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 summit image of Gorn Hill (SN 968 844)

LIDAR analysis gives the highest ground on this hill as 326.4m positioned at SN 96895 84496, and this in relation to the previously listed summit position which LIDAR analysis gives as 326.1m in height and positioned at SN 96896 84576 and SN 96896 84575 and SN 96898 84575 comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour either on Ordnance Survey maps or interactive mapping, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill 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. 

Extract from the DataMapWales interactive mapping

Therefore, the summit height produced by LIDAR analysis is 326.4m and this is positioned at SN 96895 84496, 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 78 metres southward from where the previously listed summit and the spot height is positioned and importantly the new summit position is placed in a different contour on the DataMapWales interactive mapping. 

 

The full details for the hill are:

Group:  Hirddywel 

Name:  Gorn Hill 

OS 1:50,000 map:  136

Summit Height:  326.4m (LIDAR)                                                           

Summit Grid Reference (New Position):  SN 96895 84496 (LIDAR) 

Bwlch Height:  278.1m (LIDAR) 

Bwlch Grid Reference:  SN 97747 83851 & SN 97747 83848 (LIDAR) 

Drop:  48.3m (LIDAR) 

 

Myrddyn Phillips (November 2024)