Sunday 21 June 2015

Mapping Mountains – Trimble Surveys – Mynydd Epynt


10.06.15  Cefn Bola Maen (SN 965 348), Garreg Fawr (SN 945 373), Pt. 412.8m (SN 925 349), Pt. 412.8m (SN 931 340), Coedcae Colfrân (SN 936 330), Twyn Disgwylfa (SN 951 318) and Pt. 394m (SN 958 315)    

Twyn Disgwylfa (SN 951 318)
Mynydd Epynt is a large area of uplands in southern mid Wales whose hills in its northern and western lands are out of bounds for much of the year.  These lands were acquired by the War Office in late June 1940 and subsequently used as a military firing range and named the Sennybridge Training Area.

In all the War Office acquired approximately 12,000 hectares of land and 219 people from 54 homes were uprooted.  These homes were mainly farms and the community they formed has forever gone, with many having lived on the Epynt for generations.  Some found new farms, whilst others lived out there lives heartbroken from their loss.  This sparse community was Welsh speaking and their upheaval resulted in the de-facto Welsh language border being shifted ten miles to the west.

Access through these hills has to be planned, in the past I have been fortunate and have been taken by a local farmer in his Landrover on the northern escarpment tracks late in the evening when the military had ended their day’s work.  I’ve also picked off some of the hills on this ranges eastern periphery, but the bulk of the hills within the Epynt remain unvisited by me. 

In 2004 the Epynt Way was created by the Ministry of Defence as a 75km (49 mile) long distance footpath, this footpath is circular and has been established around the perimeter of the firing range.  This long distance footpath partly compensates those who wish to visit this area as the old rights of way have been closed due to the nature of the military’s use of the land.

Today I wanted to investigate part of the southern land of the Epynt and visit four Pedwarau and two Subs and survey as many summits and bylchau as possible, in fact only one critical bwlch associated with these hills was not on my planned route and this lay northward in the firing range and was definitely out of bounds for the day.

I parked in a small lay-by just beyond Ffosygerwn which is used by a farmer to swing his vehicles into his farmyard having spoken to him beforehand.  As I got my boots on and sorted my gear out the early morning wind whipped a chill into proceedings, and I put on my one skin  summer walking jacket as my arms had got decidedly cold when I had previously spoken to the farmer.

My first hill of the day was Cefn Bola Maen and to get to it I walked on quiet narrow lanes as they meandered upward, a farmer passed on a quad bike with fresh warm milk contained in a feeding vessel for a newly arrived calf, we only spoke for a minute or so as he needed to get to the calf before the milk cooled.

I left the lane at a corner and tried to find the continuing footpath having incorrectly investigated the back of someone’s house named Troed-y-rhiw on the map which is situated below the farm of Bolamaen.  Behind me the prominent profile of the Beacons rose out of the south-Walian landscape, these hills and their distinctive shape would remain with me for the rest of the day.

The distinctive profile of Bannau Brycheiniog - the Brecon Beacons that would remain with me for most of the day
Once on open hillside the views across the intervening valley of the Nant Brân opened up with my last Pedwar of the day; Twyn Disgwylfa, a tantalising far off distance away.

The slightly raised summit of Twyn Disgwylfa in centre of photo
I headed up and crested the eastern ridge of Cefn Bola Maen and swung left toward Maen Richard.  This ancient standing stone is 1.52m high and 0.81m by 0.45m at its base.  It overlooks these southern lands and stands adrift of the hill’s summit whose whitewashed trig pillar stares back at it.  These two pillars, one ancient and the other modern signify our intrinsic need for the upland landscape.  One may have been a marker stone or a significant element of a complex ideological system, and the other a bygone element in man’s need to catalogue and lay claim to a system of height understanding.

Old and modern; the ancient standing stone of Maen Richard with the more recent construction of the trig pillar on the summit of Cefn Bola Maen in the background
As I paid my respects to the older, I then walked to the newer and did the same by supplanting its flush bracket height with a data set from a Differential GPS produced by the Trimble GeoXH 6000.

Gathering data from the summit of Cefn Bola Maen
The critical bwlch for Cefn Bola Maen is situated to its north and its position has two possibilities, each separated by an intervening 386m spot heighted lump.  Both positions were Trimbled and I continued on a good green track heading north-westward as Sky Larks and their constant mesmerising song serenaded the hills.

Looking across to the summits of Coedcae Colfrân on the left and one of the Sub-Pedwar peaks on the right
By now the first explosions of the day had started, these and copious amounts of firing continued intermittently for a number of hours afterward.  My next hill was Garreg Fawr and I wanted to survey its southern 428m spot heighted top as well as its 429m more westerly spot heighted summit.  On the way I passed the dappled waters of Llyn Dŵr with its cotton grass swaying in the breeze, it seemed a peaceful spot to rest, but I only did so for a minute, just long enough to compose three or four photos.

The blue tinged waters of Llyn Dŵr
A quiet landscape of cotton grass and water
After taking a data set from the position of the 428m spot height I pressed on through a large bog that was thankfully relatively dry, beyond was the summit of Garreg Fawr, I thought this an unusual name for such a hill unless of course a large rock existed somewhere on its summit area.  As I approached the high point of its moorland summit I noticed what looked like a small shelter of rock off in the distance, by the time I had set the Trimbe up to gather its customary five minutes of data I knew that this rock was that of Garreg Fawr and I thought its high point also needed Trimbling.

As the Trimble gathered its all-important data from the moorland summit a small herd of grazing horses approached from the east, they happily submerged themselves in the long grass.  I then went to have a look at the rock that the hill takes its name from, Garreg Fawr is indeed large.  The rock is split in two and I wondered if it is a recumbent that once stood proudly on this hill.  Whatever its history I Trimbled it and took a number of photos when doing so.

On the edge of military land with grazing horses adding peace and tranquility to the thud of distant explosions
Gathering data from the summit of Garreg Fawr
Gathering data from the top of the Garreg Fawr
I left this hill and headed westward and found the descending track that would take me down to the head of the valley at Blaendyryn.  On the way I stopped to take my jacket off as the sun had now heated up the land and the wind was now making me overheat.  The track was ochre in colour and the heat of the day gave a reminiscent feeling of walking in Greece or Spain where the sun is incessant and adds impetus to slow movement.

My route down to the valley with the ridge to the left of the distinctive copse of fir trees being my next objective
My onward route did not seem to have any right of access so I approached the farm of Maesybeddau with a little caution.  I was now next to the land border between the farms of the southern Epynt and the military firing range and a red flag flew flapping in the wind, with a large red sign proclaiming ‘DANGER KEEP OUT WHEN RED FLAG IS DISPLAYED’.

No entry when the red flag is flying
Definitely a place to avoid on red flag flying days
Thankfully the two farmers standing in the shade against the side of the farm house of Maesybeddau did not seem to mind my presence, I tried conversing with them about place-names but they seemed more interested in going indoors for their dinner, this left me standing outside and with access to the continuing track that had no right of access up it.  I quietly headed up the track and thankfully chose the right route where it diverted toward the higher farm of Rhiw.

By now the early afternoon was proving warm and I slowly made my way up the track and quietly continued past Rhiw and followed the track to its end in a field.  This then gave access through a gate back onto the higher Epynt ridge.  Away to my north another red flag flew, but my route now continued south over two Sub-Pedwar hills.

These two Subs are listed under the point (Pt.) notation in Y Pedwarau as no names seem to exist for these hills; one has 28m of drop and the other 26m of drop according to Ordnance Survey map details.  Each bwlch and summit was Trimbled, with the high point of the 413m spot heighted top being at a grassed ancient cairn, between each is the continuation of the track that leads onto the military land. 

Gathering data from the summit of one of the 400m Sub-Pedwar hills with the copse of fir trees seen from the ochr coloured track on the right of the photo
This track proved a welcome convenience and eventually led down to the bwlch of Coedcae Colfrân which is a fully fledged Pedwar with 31m of listed drop.  By now the sun was taking its toll and I walked straight over the bwlch and headed for a higher bwlch which I thought was the one that needed to be surveyed.  I soon realised my mistake and backtracked to where the critical bwlch for Coedcae Colfrân lay.  This is beside a paved road that heads over the southern Epynt from Llanfihangel Nant Brân to Pentre’r-felin and Pontsenni (Sennybridge).

As I placed the Trimble down on the track next to the narrow road I waited in the sunshine and watched the occasional car and tractor as they crested the top of the road.  Once bwlch data were gathered I followed a sheep track back up toward the next summit, the sheep track soon found a wider green track that led through a small copse of conifers to emerge onto open hillside, a gate then led onto the high pasture where the trig point at the summit of Coedcae Colfrân stands.

I placed the Trimble approximately 4 metres from the base of the trig pillar on what looked to be the high point of the hill, as all surrounding rocks at the base of the trig moved when I examined them.  I was nearing the end of my walk but still had the bwlch and summit of Twyn Disgwylfa to survey, this hill is a Hump as well as a Pedwar so it had a wee bit of ascent from its connecting bwlch, and once the Trimble was packed away it was this bwlch that I now headed down to.

Gathering data from the summit of Coedcae Colfrân
The north-western profile of Twyn Disgwylfa is invitingly appetising with a gently gradiented flank smooth with newly sprung fern and small trees edging their will up the hill.  However, this hides its bwlch which consists of a bog laden with standing water.

I contentedly approached this bwlch and pinpointed where I thought the Trimble needed to be placed from the vantage point of height.  Once at this point I had to balance between large wobbly tussocks of reed grass as the whole area is water laden.  Before placing the Trimble I photographed some of these tussocks as the afternoon light highlighted their greens.

Greens of summer
Seemingly untouched and sprouting out of a landscape of tussock and water
As the Trimble gathered its data I stood legs stretched between one wobbly tussock and another with a flatbed of water waiting for any slip.  I was very happy when five minutes of data were collected and delicately plodded from one tussock to another and retrieved the Trimble.

Gathering data in the bog which constitutes the bwlch of Twyn Disgwylfa
I considered my options through the bog and decided on the direct approach over an intervening fence and a stride over more standing water, from here I found a green path leading up hill and followed it until it disappeared near the top of the hill’s summit ridge.  I had obviously taken the wrong path option lower on the hill as by the time I reached the summit ridge I re-joined the green path, I rested whilst the Trimble gathered taken on a rock which was obviously much lower than the high point of the hill, I just needed to rest so why not gather data when doing so?

I slowly plodded along this ridge past the first potential high point which is immersed in gorse, to the next two potential high points; the latter two are attractive and are situated near two pools which have cairns built on them, with the stones seemingly floating on the water.

One of the two attractive pools on the summit area of Twyn Disgwylfa
Both of these potential high points are thankfully situated on grass, away from the influx of gorse which is widespread on the upper part of this hill.  Both positions were Trimbled and as I waited for the allotted five minutes of data to be collected I looked out to the higher hills away to my south and west as the sun sank ever deeper in the western sky.

Gathering data from the summit of Twyn Disgwylfa
I thought that these would be my last surveys of the day but as I examined the map for my descent route I noticed that the next bump on the ridge was a potential double Sub-Pedwar, so I thought why not survey it.  This I duly did and happily sat on a grassed bank waiting for the Trimble to gather bwlch data and stood in the breeze and sunshine at the summit as it gathered its last data set of the day.

Looking back toward Twyn Disgwylfa
The 18th and last data set of the day
As I headed down the green track from this last survey the Beacons stood out to the south, their profile one of eloquent shape, with their hills set against a foreground of greenery and yellowed gorse. 

Evening light on Bannau Brycheiniog
When the track bisected I took the left hand option and followed it down through part of Coed y Rhiw-las back to my car, with the ever present sun casting through the trees a pleasing colour of contentment.


My route back to the car

Survey Result:


Cefn Bola Maen

Summit Height:  421.9m (converted to OSGM15)

Summit Grid Reference:  SN 96510 34812

Bwlch Height:  375.3m (converted to OSGM15)

Bwlch Grid Reference:  SN 96472 35794

Drop:  46.6m

Dominance:  11.05%




Garreg Fawr

Summit Height:  428.7m (converted to OSGM15)

Summit Grid Reference:  SN 94536 37354

Bwlch Height:  c 396m (interpolation)

Bwlch Grid Reference:  SN 94843 40061 (interpolation)

Drop:  c 33m

Dominance:  7.62%




Pt. 412.8m

Summit Height:  412.8m (converted to OSGM15)

Summit Grid Reference:  SN 92523 34928

Bwlch Height:  385.2m (LIDAR)

Bwlch Grid Reference:  SN 92403 35561 (LIDAR)

Drop:  27.6m (Trimble summit and LIDAR bwlch)

Dominance:  6.69% (Trimble summit and LIDAR bwlch)




Pt. 412.8m

Summit Height:  412.8m (converted to OSGM15)

Summit Grid Reference:  SN 93184 34035

Bwlch Height:  385.3m (LIDAR)

Bwlch Grid Reference:  SN 92897 34689 (LIDAR)

Drop:  27.5m (Trimble summit and LIDAR bwlch)

Dominance:  6.66% (Trimble summit and LIDAR bwlch)




Coedcae Colfrân (significant name change)

Summit Height:  408.3m (converted to OSGM15)

Summit Grid Reference:  SN 93612 33065

Bwlch Height:  377.2m (LIDAR)

Bwlch Grid Reference:  SN 92953 33459 (LIDAR)

Drop:  31.1m (Trimble summit and LIDAR bwlch)

Dominance:  7.62% (Trimble summit and LIDAR bwlch)




Twyn Disgwylfa

Summit Height:  416.7 (converted to OSGM15)

Summit Grid Reference:  SN 95132 31863

Bwlch Height:  315.9m (LIDAR)

Bwlch Grid Reference:  SN 93709 32589 (LIDAR)

Drop:  100.8m (Trimble summit and LIDAR bwlch)

Dominance:  24.19% (Trimble summit and LIDAR bwlch)




Pt. 393.7m

Summit Height:  393.7m (converted to OSGM15)

Summit Grid Reference:  SN 95885 31534

Bwlch Height:  373.8m (converted to OSGM15)

Bwlch Grid Reference:  SN 95425 31655

Drop:  19.9m (non 390m Double Sub-Pedwar and non 300m Sub-Twmpau 

status confirmed)

Dominance:  5.06%




For further details please consult the Trimble survey spreadsheet click {here}

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