Tuesday, 13 October 2026

Mapping Mountains – Significant Name Changes – 100m Twmpau


Ffridd Uchaf (SH 799 668) 

There has been a Significant Name Change to a hill that is listed in the 100m Twmpau, 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 Ffridd Uchaf (SH 799 668)

The criteria for the list that this name change applies to are:

100m Twmpau - Welsh hills at or above 100m and below 200m in height that have 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 100m and below 200m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

100m Twmpau by Myrddyn Phillips

The hill is adjoined to the Mynydd Hiraethog group of hills, which are situated in the northern part of North Wales (Region C1, Sub-Region C1A), and it is positioned encircled by minor roads with the A470 road farther to its west, and has the town of Llanrwst towards the south.

When the original 100m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category.

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed under the point (Pt. 182m) notation with 27m of drop, based on the 182m summit spot height and the 155m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

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

As the summit of this hill comprises bounded land the details for it were examined on the Tithe map.  The term Tithe map is generally given to a map of a Welsh or English parish or township and which was prepared after the 1836 Tithe Commutation Act.  This act allowed tithes to be paid in cash rather than goods.  The Tithe maps gave names of owners and occupiers of land in each parish and importantly for place-name research they also included the name of enclosed land.  This enclosed land is usually based on a field system, however not every field is given a name, but many are and especially so in Wales. 

Extract from the Tithe map

The enclosed land where the summit of this hill is situated is given the number 575 on the Tithe map, this can be cross referenced against the apportionments; it is these apportionments that give the name of the owner or occupier of the land as well as the name of the land.  The land where the summit of this hill is situated is named Ffridd Uchaf the apportionments, with the details on the Tithe map appearing in the parish named as Eglwys-fach and in the county named as Caernarfon. 

Extract from the apportionments

Therefore, the name this hill is now listed by in the 100m Twmpau is Ffridd Uchaf, and this was derived from the Tithe map. 

 

The full details for the hill are:

Group:  Mynydd Hiraethog

Name:  Ffridd Uchaf

Previously Listed Name:  Pt. 182m   

OS 1:50,000 map:  115

Summit Height:  182.4m (LIDAR) 

Summit Grid Reference:  SH 79916 66826 & SH 79918 66824 (LIDAR) 

Bwlch Height:  155.8m (LIDAR) 

Bwlch Grid Reference:  SH 79340 66846 (LIDAR) 

Drop:  26.6m (LIDAR)

 

Myrddyn Phillips (October 2026) 

Saturday, 10 October 2026

Mapping Mountains – Hill Reclassifications – The Fours – The 400m Hills of England

 

Foggintor Quarry (SX 566 735) – Sub-Four addition

There has been an addition to the listing of 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 conducted by Myrddyn Phillips. 

LIDAR image of Foggintor Quarry (SX 566 735)

The criteria for the list that this addition 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 is a sub list entitled the Sub-Fours, the criteria for which are all English hills at or above 400m and below 500m in height that have 15m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available to download in Google Doc format from the Mapping Mountains site.

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

The name the hill is listed by is Foggintor Quarry, and it is adjoined to the High Willhays group of hills, which are situated in the south-west of England, and it is positioned with the B3357 road to its north and the B3212 road to its south-east, and has the town of Tavistock towards the west.

When the Introduction to the first group of hills for the updated and revised listing of the The Fours – The 400m Hills of England was published by Mapping Mountains on the 10th September 2022, it was announced that the accompanying sub lists were being revised with the two 390m categories dispensed with and the criteria and name of the 400m Sub-Fours revised.  The one accompanying sub list is now named the Sub-Fours with its criteria being all English hills 400m and above and below 500m in height that have 15m and more and below 30m of drop.

Prior to this revision this hill was not listed, with subsequent interpolation giving it an estimated c 8m of drop, based on an estimated c 403m summit height and an estimated c 395m col height, with both heights based on interpolation of 10m contouring that appears on the Ordnance Survey 1:25,000 Explorer map, with the caveat that due to the Ordnance Survey protocol of contouring at quarries, these are not continuous and therefore difficult to interpolate. 

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-Four status is due to LIDAR analysis, resulting in a 408.2m summit height and a 392.9m col height, with these values giving this hill 15.3m of drop, which is sufficient for it to be classified as a Sub-Four. 

 

The full details for the hill are:

Group:  High Willhays

Name:  Foggintor Quarry

OS 1:50,000 map:  191

Summit Height:  408.2m (LIDAR)

Summit Grid Reference:  SX 56651 73554 (LIDAR)

Col Height:  392.9m (LIDAR)

Col Grid Reference:  SX 56659 73630 (LIDAR)

Drop:  15.3m (LIDAR)

 

For the additions, deletions and reclassifications to The Fours – The 400m Hills of England reported on Mapping Mountains since the December 2013 publication of the 1st edition of this list by Europeaklist please consult the following Change Registers:

 

The Fours

 

Sub-Fours

 


Myrddyn Phillips and Aled Williams (October 2026)              


Wednesday, 7 October 2026

Mapping Mountains – Trimble Surveys – Mynydd Epynt

 

07.06.26  Ysgwydd Hwch (SO 052 379), Lan (SO 052 391) and Yr Allt (SO 059 390)

Yr Allt (SO 059 390)

This year’s Relative Hills Society (RHSoc) dinner was held in The Wellington Hotel in Brecon.  It was the first time I had attended since my guest speaker slot at Shifnal a few years ago.  The evening was very enjoyable and especially so as our Y Pedwarau table won the quiz.  Afterward I sauntered back to my car to find a quiet spot to overnight.  This was next to a waste disposal site, which doesn’t sound very pleasant, but the area was quiet and out of the way with only one car passing the junction at the end of the road as I prepared my bed for the night with stars appearing in a clearing sky.  The following morning after boiled eggs and samosas for breakfast I drove to Talgarth to the New Gurkha Inn to meet Mark Trengove, who had over-nighted there.  After his breakfast and packing his car we headed off to the hills. 

A nice quiet spot to spend the night

Our plan for the day were three forested Pedwar hills to the north of Talgarth, and as the days forecast gave strong blustery wind the confines of the forest would at least give us shelter.  Our first attempt at finding our parking place ended in failure with me leading the way and trying to navigate with an OS map.  We ended up back on a main road having driven about six miles on narrow country lanes.  Our second attempt was led by Mark using his SatNav, this thankfully proved successful and soon my car was parked at the start/end of a forest track to the north-east of the small community of Llaneglwys.  Mark then drove to the start of our walk which had a convenient small parking area and picnic tables.

Close to where Mark parked his car was the forest track leading to our first hill of the day.  We set off walking at 10.40am, with the wind blowing and if the forecast was correct, dry overhead conditions until late in the afternoon when more rain was predicted to head in from the west.

A clearing on our left gave views looking south toward the high Beacons, except for Pen y Fan all just clear of the grey murking cloud.  It made a tranquil scene with greened fields as foreground, and all the more so as we didn’t expect many opportunities for extensive views during the entirety of the walk due to the confines of the conifer plantation we were now walking up in to. 

Looking out toward the high Beacons

As we approached the first summit and our high point of the day; Ysgwydd Hwch, we encountered a section of felled forestry, this gave a semblance of view.  But as usual such places are scattered with tree debris that is both an unruly mess to look at and also a hell to walk through.  Thankfully the continuation of the access track we were now on which led toward a tall mast and small compound made our upward progress relatively easy. 

Mark heading on the access track toward the summit of Ysgwydd Hwch

Approaching the summit of Ysgwydd Hwch

The area of the high point was not difficult to find and aided by the ten figure grid reference attained from LIDAR analysis we were soon standing on the summit.  Shortly afterward I had the Trimble assembled and gathering data.  However, as I stood below the equipment I considered this position to consist of accumulated debris and therefore man-made, because of this I took a second data set a few metres away at the base of a tree stump. 

Gathering data at the first of two set-up positions at the summit of Ysgwydd Hwch

Once data were gathered and stored I closed the equipment down and as I was just getting ready to take a few photographs I saw a figure standing beside the edge of the small compound enclosing the mast, he was smiling and waving my way; it was Alex Cameron who had also been at the dinner last night and who was on one of his mammoth overnight walks with these same three hills his destination.  I hadn’t seen Alex on the hill in quite some time and although Mark and I had wondered if any other fellow hill bagger may be on these hills today, it was still a surprise to see him.  Hugs were had and we continued the rest of the walk as a threesome. 

The second of two set-up positions at the summit of Ysgwydd Hwch with Alex the unexpected visitor in the background

Our onward route was now following forest tracks north-eastward before swinging west where our track bisected another coming in from the south which was an alternate option to get us from the summit of Ysgwydd Hwch to this point.  On the way the view opened toward our next two hills.  From this direction they looked deeply forested, but thankfully the trees on each were mature and proved easy to walk through and therefore reach the summit of each hill.  All around was greenery with succulent ferns and moss encrusted old branches backed by the strong wisps of wind that cascaded over the hills. 

On the forest track between Ysgwydd Hwch and the small pool

Summer greenery

Lan (SO 052 391)

As we lost height part of the forest had been felled with the diggers in situ awaiting the next working day and the logs neatly stacked awaiting removal.  Close to was a small pool that Mark had spotted, we stood beside it for a few minutes enjoying the tranquil scene. 

The forest track leading down toward the small pool

Mark beside the small pool

The next part of the walk was back on to the continuation of the forest track as it headed uphill.  For me I was now in head down and plodding mode.  Gone are the days when I could tackle such ascents relatively easy and quickly, a sad indictment of getting older when the body and its capabilities change.  Soon we turned right on to a green track which in time led to a narrow path on our right leading in to the main conifer plantation.  The narrow path was part of a series of mountain bike trails through these woods, with others evident in a few places.  All were welcome and this one was a delight to walk on as it took us forever higher through the wood.  The path eventually swung around and ended up within a few metres of the high point of this our second hill of the day. 

Entering the wood on our way to the summit of Lan

This hill was originally listed by the name of Llaneglwys Wood.  A name I invented when the Welsh 400m hills were first compiled.  Its listed name was changed to Lan in 2016 when Aled consulted the Tithe map and this is how it has appeared in the Y Pedwarau – The 400m Hills of Wales list ever since. 

The Trimble GeoXH 6000 positioned at the summit of Lan

Having reached the top it was time to have a rest.  Alex sat and took his boots off to give his feet time to heal from those many hours of overnight walking, whilst Mark and I pottered about checking grid references and judging any potential high point for their claim to be the summit position of the hill.  Having chosen our preferred candidate I positioned the Trimble on top for the customary photograph.  I had no intention of trying to gather data from this summit due to the overhead canopy of trees and therefore soon joined the others for a restful few minutes having lunch. 

Time to rest

As the remains of my treats consisting of a Polish sausage and oat biscuits were packed away, it was time to set off and Alex led the way on the continuation of the narrow mountain bike trail as it quickly lost height heading in the direction of the green track that had given us access to the upper part of the hill.  The path was more indistinct on this side of the hill, but nonetheless still easy to follow. 

Heading down from the summit back on to the green track

Having regained the green track, it soon veered left and then immediately right and now continued with an open field on our right.  This part of the walk I found particularly beautiful as the long grass in the field swayed to the rhythm of the wind.  We stopped to take photos of the conifered upper part of our last hill of the day; Yr Allt which is another name derived from the Tithe, with the farm to the south giving the name of the hill away; Danyrallt, under the allt. 

Yr Allt from the connecting green track between it and Lan

By now I was progressively getting slower compared to Alex and Mark.  Alex is a strong walker and even with a large heavy rucksack was much quicker than me during the whole walk, whilst Mark is a good steady walker and who kindly waited for me to come in to view at any major turn to make sure that I did not overshoot as I brought up the rear. 

On the green track leading to the narrow path on our right in to the wood

We now headed in to the wood on what looked like a form of path; however we soon left this and headed up through the trees with Mark guiding the way toward the summit with the aid of his hand-held GPS.  Thankfully the summits of Lan and Yr Allt are both within mature forest, making walking between the trees easy.  I found this delightful and such a change from what can become an unruly obstacle course when further progress up or many times even down, seems next to impossible due to the confines of conifer trees. 

Extraordinary mosses on our way through the wood to the summit of Lan

Having reached the summit we did the customary things, stopped, chatted, took a few photos and then debated the best way to get off the hill and back to my awaiting car.  We had a couple of options and eventually decided to backtrack to the inward green track, this continued down the hill but was seemingly barred from further progress due to one of the rare felled trees across the path that we encountered during the day.  Mark considered backtracking and taking a detour, but thankfully Alex went ahead to investigate and once on the other side called us on. 

The summit of Lan

The green track swung southward around the eastern face of Yr Allt and then doubled back on itself now heading north-eastward and all the time loosing height.  This again was a delightful part of the walk, easy underfoot with occasional brambles and nettles to bi-pass, all of which were easy to avoid and all the time the greenery of summer was on display with succulent growth appearing all around.

We were nearing the end of the walk; all that remained was finding a way down on our right either over a barb wired fence giving access through a long grassed field down to the minor road close to where my car was parked, or another route down which Alex and Mark were now investigating.  This consisted of yet another delightful narrow path on the edge of the wood and beside the boundary fence with the field beyond. 

Mark on the narrow path leading back to the forest track and the car

We stopped for a few minutes as the view opened toward the masted summit of Ysgwydd Hwch.  From this direction the whole upper hill seemed to consist of a mass of confined forestry, as indeed all three hills seemed to be so from a distance.  Thankfully for the enjoyment of today’s walk each proved otherwise. 

Ysgwydd Hwch (SO 052 379)

We were soon at my car, and a few minutes later at Mark’s car at the small picnic area.  All that remained was the drive back to Welshpool and three welcome mugs of tea before Mark took Alex to Flint railway station for his train home.  It had been another good day on the hill in the company of two good friends with another three Pedwar hills visited. 

 

Survey Result:

 

Ysgwydd Hwch

Summit Height:  455.7m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SO 05233 37909 (Trimble GeoXH 6000) 

Bwlch Height:  386.6m (LIDAR)

Bwlch Grid Reference:  SO 03872 38847 (LIDAR)

Drop:  69.0m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  15.15% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

Lan (significant name change)

Summit Height:  413.9m (LIDAR) (significant height revisions) 

Summit Grid Reference:  SO 05239 39141 (LIDAR) 

Bwlch Height:  377.2m (LIDAR)

Bwlch Grid Reference:  SO 04853 39386 (LIDAR)

Drop:  36.7m (LIDAR) (400m Sub-Pedwar reclassified to Pedwar)

Dominance:  8.87% (LIDAR)

 

 

Yr Allt (significant name change)

Summit Height:  407.0m (LIDAR) 

Summit Grid Reference:  SO 05914 39093 (LIDAR) 

Bwlch Height:  364.7m (LIDAR)

Bwlch Grid Reference:  SO 05578 39234 (LIDAR)

Drop:  42.3m (LIDAR)

Dominance:  10.39% (LIDAR)

 


My thanks to Alan Dawson with help processing these data


For further details please consult the Trimble Survey Spreadsheet