Mapping Mountains – Trimble Surveys – Arenig Fawr

13.12.25  Ffridd Trawsgoed (SH 837 328) and Moel Hafod yr Ŵyn (SH 841 322) 

Moel Hafod yr Ŵyn (SH 841 322)

There is bleak beauty in venturing on to rough, unremitting ground and especially so during the onset of winter where grey skies predominate and a brisk wind echoes across the land.

Today we visited two hills positioned just west of the southern most part of Llyn Tegid.  Both are relatively easy to access from the narrow road that winds its way across these hills toward Bronaber.  I hadn’t been on this road in many years and had not until today visited these two hills.

I met Mark and Aled in Y Bala, where we left two cars and then continued on the A494 road heading south-west beside the lake toward the minor road that in time would take us to our designated parking spot on a grass verge beside an old metal gate. 

Heading toward the forest track

The forecast gave south-westerly winds, so not chilled and relatively mild for the time of year.  I set off before Mark and Aled, but soon stopped and waited as the continuation of the way up the hill was indistinct with slender long grasses amongst bracken and stunted trees giving little indication of a path.  However, one did exist and once on it I followed my companions up to a forest track that shortly afterward bisected another track where a person was standing beside a gate.  As we approached we said hello; Andrew Graham was the landowner, his sister was standing a short distance further down the track.  We chatted for five minutes or so, he was concerned as the gate had been left open and wondered who had done it.  He’d come to the area in the 1960s having bought the land to turn it over to the conifer plantation that now surrounded us. 

Andrew Graham

As Andrew walked down the track to join his sister, we headed in the opposite direction looking for a convenient access point on to the upper hill, which now rose in front of us a mass of heather and roughness.  The going uphill from this point was steep and ponderous with no semblance of path.  It was hard work, but also a marvelous place to find oneself on a Saturday afternoon in December. 

The steep heathery slopes leading to the summit of Ffridd Trawsgoed

I arrived on top last out of the three and was immediately buffeted by the brisk wind.  Although I’d brought the Trimble I had little intention of using it unless the tops were covered in clag and then only as a hand-held GPS device.  However, I still placed it on the high point for the customary photograph. 

The summit of Ffridd Trawsgoed

To our south Moel Hafod yr Ŵyn looked a wild inviting hill, with a rather unpleasant bog between us and it.  Leaving the summit we stumbled our way down the steep pathless slope and back on to the relative comfort of the forest track.  However, the comfort didn’t last long as soon the bog would have to be tackled. 

Moel Hafod yr Ŵyn and its unsavoury looking bog

There’s a pleasing aspect to bogs.  Many are lush with copious amounts of undergrowth and this one was definitely one to savour.  Progress through it was never difficult and wearing vibram soled wellies certainly helped.  I followed Aled as he furrowed his way through, only stopping occasionally to regather my breath during which I looked at the slender threads of long grasses as they gently danced in the wind.  As I said; there is beauty in a bog. 

Mark tackling the bog

Mark soon joined us on the other side of the bog and as Aled headed up to gain height, Mark continued flanking the upper hill on the periphery of the bog before then heading up toward the summit cone.  Oh decisions decisions, what one to follow?  I opted for Aled and was soon being left behind as I made slow progress through the undergrowth.  By the time I spotted Mark he had gained height and was approaching the upper part of the hill, Aled was already nearing the summit.  I continued my slow plod up in to the realms of wind and views.

Aled heading toward the summit of Moel Hafod yr Ŵyn

The upper cone of Moel Hafod yr Ŵyn

The upper hill proved a delight with a small rock band to veer past.  Having reached the summit I did as I had done on top of Ffridd Trawsgoed and placed the Trimble on the high point for its customary photograph.  The view compensated for my tiredness, with the land to the west a wild and remote place of more tussocks, bog and rising hills, whilst to our south-east the descending slopes headed down to the gentler climes of the valley below. 

The summit of Moel Hafod yr Ŵyn

Leaving the high point I followed Aled down through mixed ground of heather and intermittent hidden rock.  Our route down led to a wall which had a barb wired fence perched menacingly on top of it.  This was not good news for the two elderly gentlemen in our walking party.  However, with the help of our younger colleague there was no mishap and soon we were standing on relatively safe ground on the other side. 

The last steep slope leading back on to the narrow road and the car parked beyond

From here it was only a short walk back to the car; with an initial steep slope leading on to the narrow road where we veered right and followed the thin width of tarmac a few hundred metres back to where we had started our walk from.

We were back in Y Bala at around 4.40pm and soon happily seated in the Plan yn Dre for an early evening festive meal, which proved an excellent way to end another good day on the hill. 

 

Survey Result: 

 

Ffridd Trawsgoed 

Summit Height:  423.9m (LIDAR)  

Summit Grid Reference:  SH 83755 32841 (LIDAR)

Bwlch Height:  384.2m (LIDAR)

Bwlch Grid Reference:  SH 83731 33086 (LIDAR) 

Drop:  39.7m (LIDAR)

Dominance:  9.36% (LIDAR)

 

 

Moel Hafod yr Ŵyn 

Summit Height:  398.2m (LIDAR) (significant height revision)  

Summit Grid Reference:  SH 84199 32238 (LIDAR)

Bwlch Height:  358.4m (LIDAR)

Bwlch Grid Reference:  SH 84033 32465 (LIDAR) 

Drop:  39.8m (LIDAR)

Dominance:  9.99% (LIDAR)

 

 

For further details please consult the Trimble Survey Spreadsheet 

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

Mapping Mountains – Trimble Surveys – Carnedd Llywelyn

16.11.25  Foel Lus (SH 732 761) 

Foel Lus (SH 732 761)

In October 2018 I visited the lower hills of the north-eastern Carneddau during a 7 hour walk, taking in six hills, all of which were surveyed.  From the most westerly of these; Allt Wen (SH 745 772) I looked out across the intervening plain toward Foel Lus.  On that day the sky merged with the sea, all a glorious blue and Foel Lus peered back at me as a great inviting rounded lump of a hill.  I promised myself that one day I would visit.  Seven years later and that promise has finally been fulfilled.

I’d spent the previous evening in the company of the Steads, with Darrin celebrating his 60^th birthday with wife Lisa, sons Tom and Will, and Tom’s girlfriend Lizzie.  It’s always good to see Lisa and Darrin, with past travels around Peru and Bolivia and lots of hill walks a reminder of our friendship.  The evening was great fun with lots of chat and silly games, all of which brought many laughs.

Just before breakfast I sorted my gear and checked the route to the hill, which was easy from where we were staying as it was only a matter of following the road around and then down, turning right and continuing up the ever increasingly steep Mountain Lane to its end where a rough track continues up toward Ty’n-y-ffrith farm.  I left the Steads having thanked them for a lovely evening as they were heading off for a walk to Aber waterfall before Will caught the afternoon train back to Leeds.

There were already two cars parked at the end of the lane when I arrived.  Beside one was a customised E-bike with some of the widest tyres imaginable, its owner was sitting on a near bench enjoying the view whilst having a bite to eat.  I sauntered over and chatted with him for a few minutes before gathering my rucksack and heading on the circuitous route around the hill.

According to the contours on my OS map, where I parked was around 250m high and with the hill being 360.0m in height, the walk wasn’t going to be too taxing.  That suited me as I was in a relaxed mode of travel with few worries fluttering around inside my head, and except for beating darkness on the drive home I wasn’t in a rush, which even on the slowest of slow walks I could easily accomplish.  Therefore, I happily headed off following a broad path heading initially north-westward around the hill. 

On the initial section of path

The weather forecast was good for the day, although high cloud only thinned later on and therefore there were few flashes of direct sunlight on the autumnal colours that still lingered amongst the land.

Away out to sea the elongated profile of Ynys Seiriol floated on the near horizon with the flatness of water seemingly enfolding Foel Lus.  There’s a special quality to walking beside the coast, this is prevalent whether beside the sea or elevated above it.  Its flat realms seem to add unexpected perspective to any view, and today my increasingly elevated position above the north Wales coast was one to be savoured.

The path continued contouring around the hill to its north, with the view now opening up to the north-east toward Allt Wen and its adjacent hills bringing memories of the walk I did in 2018.  On my way I passed a number of memorial plaques adorning the near rock, beside one was a small cave, and another a bench where no doubt people come, sit, remember and out across the expanse of sea disappearing in to the beyond. 

The memorials beside the path

As I crested the furthest north-easterly point of the path and just as I headed southward on it, a young guy appeared walking toward me from a slightly lower path, I said hello and tried to engage him without much luck as only a monosyllabic reply came my way.  Later as I plodded up the path leading to the summit he was already heading down, again little came my way except for a grunt of a ‘yes’ when I smiled and asked if he’d already been to the top.  I suppose it takes all sorts and perhaps he just wanted the solitude without a customary hello from a passing stranger. 

Gogarth is the distance with Allt Wen on the right

I took my time on the uphill and savoured the environment and rather ironically; the solitude!  Just before the high point I diverted to a prominent cairn giving views forever downward and across the sea.  The top of the hill was not far away and when I arrived it was for all too brief a moment bathed in direct sunlight emanating from a dappled and milky sky that clung above Tal y Fan to my south, with the ridges of the higher Carneddau peaks still cloud enshrouded beyond. 

The Gwynt y Môr wind farm

I stayed on top for a few minutes, having previously LIDARed the hill I did not bring the Trimble.  I’ve found the need to survey hills dimming in my old age, and have started to experience and enjoy the freedom that not always carrying the Trimble can give.  However, I found myself assessing the lay of land close to the summit windshelter for where I considered the high point of the hill was situated.  This made me smile as even without the Trimble it seems some habits are hard to break. 

The summit of Foel Lus

On my way down I said hi to a cyclist who was making good progress heading up.  He’d just overcome one of the steepest parts of the path and all without getting off his bike.  Two others had already passed me on my way up; I had then turned and watched them rhythmically curving their way down.  They seemed at one with the path as they swung left and then right, forming a pattern as the one behind quickly repeated what the other in front had just done.  I admired their skill, as I did with the cyclist now heading up the hill.  I remember my mountain bike days when downhill brought excitement and trepidation; this always seemed to be over too quickly before the next tiring uphill was tackled.  This gave little time for photography, which was one of the main reasons for concentrating more on hill walks.  Still, the outdoors is enjoyed by people doing many different activities and cycling off road brings its own exciting form of pleasure. 

Foel Lus from the south

I all too quickly left the rock strewn path and found my way on to a greened canvass which continued southward, here I veered right and followed a steepening rough track down to where my car was parked. 

Ynys Seiriol with the last remnants of autumnal colour in the foreground

Foel Lus certainly didn’t disappoint and proved an ideal way to end an excellent weekend. 

 

Survey Result: 

 

Foel Lus 

Summit Height:  360.0m (LIDAR) (significant height revision)  

Summit Grid Reference:  SH 73238 76184 (LIDAR)

Bwlch Height:  299.9m (LIDAR)

Bwlch Grid Reference:  SH 73386 75791 (LIDAR) 

Drop:  60.1m (LIDAR)

Dominance:  16.69% (LIDAR)

 

 

For further details please consult the Trimble Survey Spreadsheet 

Mapping Mountains – Trimble Surveys – Mynydd Epynt

18.05.25  Pen y Crug (SO 029 303) 

Pen y Crug (SO 029 303)

Hill celebrations are always wonderful occasions.  They are culminations of what for many people are years of ticking off hills in a list.  They are also occasions when old and new friends meet, and if combined with beautiful weather, as today was, they can be a shear joy to experience.

Today was the finish of Mark Trengove’s Welsh Hump completion.  For the uninitiated, a Hump is a 100m prominence hill.  There are 368 qualifying Welsh hills that meet this criterion and the one Mark had singled out for his last was Pen y Crug, which connects with the Mynydd Epynt group of hills.  Although much of this hill range is out of bounds due to a military training area, Pen y Crug is positioned on the southern periphery and well away from any out of bounds land.

I had been up the hill once before, in September 2017, when Lou and I ascended from the south-east on a good track that turned to a friendly green path leading up through the autumnal colour to the trig pillar that sits atop the summit.  On this day the tops of the higher Beacons were just skimmed with cloud, otherwise the hill gave excellent views.  Today the sky was an unadulterated blue with skylarks singing above and a welcome slight breeze cooling proceedings.  It was a perfect day for a hill celebration.

Mark drove from Mold to Welshpool, from where I then drove south to the car park at the base of the hill to its north.  This was close to its bwlch and gave me a chance to experience the hill from a different perspective and approach, which I always enjoy.

Our meeting time was midday and we arrived with 20 minutes to spare.  Soon cars started to appear, Rick and Jenny, Brent Lynam, Alex Cameron and Tony Jenkins soon arrived, followed by Barry Smith, Chris Bienkowski, Adrian Rayner and Keith Anderson.  It was good to see all, many who I had not seen for quite sometime.

I made an excuse to wander off to take a few photos of the hill, and asked Mark to keep everyone at bay for a few minutes; this gave me opportunity to head in to an adjacent field to get a few photographs, but also gave opportunity to gain a few minutes on everyone else and sneak away for a leisurely plod up the path leading to the open hillside above.

It felt good to be out in the sunshine, slowly wandering taking in the surrounds with skylarks singing, bees buzzing and bluebells and greenery all around, and all with the backdrop of the blue sky.  The path led up with greened hedgerows either side and manicured grazed fields beyond.  The enclosed path gave views directly toward the higher hill, which loomed above in a gently curved profile.

The path led to a gate which gave access to the open upper hill, from where an earthen dried path contoured up giving extended views past hillsides of bluebells to the light grayed ridges of the Black Mountains away to the east. 

The view east toward the Black Mountains

My pace was leisurely and all too soon I was caught by the throng of people following.  We soon crested the ridge that affords views south toward the higher Beacons.  Beyond the greened path led toward the ancient embankment and ditches that encircle the upper hill. 

I was soon caught up

Arriving at the summit we waited for Mark, who sauntered up behind us.  As he approached the high point there was a guard of honour waiting for him, with raised walking poles leading him over the summit of the hill toward the trig pillar.  He’d completed the Welsh Humps.  

Mark approaching the summit of Pen y Crug

All hill lists can take you on a journey to places that otherwise you would not visit; this is part of their appeal.  There is of course the small bonus that hills can afford tremendous experience and I’m sure the Welsh Humps have given Mark some excellent days on the hill. 

The guard of honour leading Mark to the summit

The next hour was one of those special occasions on the hill, with lots of conversation small glasses of Welsh whiskey, cake, strawberries and lots of nibbles and photos. 

Mark celebrating his completion of the Welsh Humps

During our time on the summit someone mentioned that Pen y Crug was also Adrian’s 7,000 Tump.  Another remarkable achievement and soon Adrian was beside the trig pillar kindly posing for a few photos.  He had kept this quiet, allowing for Mark’s celebration. 

Adrian at the summit of his 7,000th Tump

After we had finished off much of the celebratory food and drink things started to be packed away and as we waved Rick and Jen off down the hill, the rest of us followed ten minutes or so afterward. 

A nice touch brought by Mark for cake adornment

Leaving the summit we headed north down the upper part of the hill until connecting with the earthen ramparts, and then followed these around the hill, before connecting with our inward route and following this back down through the heat of the afternoon to the awaiting cars below. 

At the summit of Pen y Crug, from left to right we have; Bryher, Rick, Jenny, Barry, Alex, Keith, Adrian, Tony, Brent, Chris and Mark

It had been an excellent time on the hill and was rounded off with a visit to a pub on the outskirts of Brecon for a good meal and more interesting conversation. 

 

Survey Result:

 

Pen y Crug 

Summit Height:  331.2m (converted to OSGM15) (previous Trimble GeoXH 6000 survey)  

Summit Grid Reference:  SO 02927 30312 (previous Trimble GeoXH 6000 survey)

Bwlch Height:  219.9m (LIDAR)

Bwlch Grid Reference:  SO 02162 30880 (LIDAR) 

Drop:  111.4m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  33.62% (Trimble GeoXH 6000 summit and LIDAR bwlch) (Lesser Dominant addition)

 

 

For details on the summit survey of Pen y Crug

For further details please consult the Trimble Survey Spreadsheet 

Mapping Mountains – Trimble Surveys – Moel y Gamelin

 

27.01.24  Caer Drewyn (SJ 091 444) 

Caer Drewyn (SJ 091 444)

The high point of Caer Drewyn is listed as a Subhump and Trichant.  This would be enough to encourage many a hill bagger to visit, but it is the remains of the Iron Age hill fort that is the main attraction.  The stone walled construction is perfectly placed overlooking two river valleys, with the Afon Dyfrdwy (River Dee) to its south and a tributary to its west.

Cofein reports that the hill fort had three phases of construction, with the initial part surviving as an earthwork to the north-east of the main construction and which is evident close to the high point of the hill, which is known locally after its main feature of the ancient hill fort; Caer Drewyn. 

Mosaic of Caer Drewyn outside the leisure centre in Corwen

The summit of this hill had previously been surveyed by John Barnard and Graham Jackson and it was this that was our objective for the day, that and a meal and catch up and a few hours spent in good company.  We met in Y Bala and wandered in to town for a hearty breakfast in Hoffi Coffi.  After an hour or so of nourishment and conversation we took two cars north-eastward to Corwen and parked on the northern side of the river in the leisure centre car park.  This would enable Mark to head directly back to Mold after the walk and for Aled to drive back to Y Bala where my car had been left, before he continued to Porthmadog and I headed home to Welshpool.

Making our way up the muddied narrow lane

From the convenience of the car park it’s not a great distance to the top of Caer Drewyn, however it is steep and especially so if opting for the direct path, which we followed.  But before the steep part we leisurely walked past the entrance to the leisure centre with me setting a comfortable slow plod at the back, before venturing a short distance up the B5437 road which was closed to traffic beyond its intersection with the bridge that crosses the river to the centre of Corwen.  Beyond the intersection we took the first left and headed up a muddied narrow lane to where a public footpath sign indicated the start of the steep uphill. 

The view south-west during the ascent of Caer Drewyn

Thankfully with a few stops to regain breath and enjoy the ever expanding view the steep bit was not too taxing.  This brought us over a green lane which we used as our descent route before continuing up to the remains of the walled enclosure.  The view extended toward Aran Fawddwy and the pyramidal coned summit profile of Arenig Fawr, and although conditions were overcast both were clear of cloud.  Sadly the sun did not give colour to the land until we arrived back at the cars, but this did not detract from the views, however just a little flash of sunlight can add so much to an overcast day and especially so at this time of year, when the land can become illuminated with the slightest direct sunlight. 

Mark and Aled making their way up the ancient embankment

As Mark and Aled followed a path on the ancient embankment, I kept to another path just below, with each joining near the top of the main walled enclosure.  The high point of the hill was just beyond with a slight descent to a gate and then a manicured green field leading to the summit of the hill. 

The field leading to the summit of Caer Drewyn

The high point of Caer Drewyn consists of a small mound with embedded rock.  I soon had the Trimble aligned with its high point and quickly measured the offset between its internal antenna and the ground at its base, and when the 0.1m accuracy level appeared on the screen I pressed Log and walked away so as not to disturb satellite reception. 

The Trimble GeoXH 6000 gathering data at the summit of Caer Drewyn

Once the equipment had done its stuff and was packed away, only the descent remained, which for me now meant I could at least talk, with much of the uphill consisting of a huff and a puff.  Reversing our inward route to the gate we then followed the green track as it gently lost height and zig zagged around the hill regaining our inward route at the muddied narrow lane.  It proved an ideal hill to visit for this time of year and two hours after setting off we were back at the awaiting cars. 

 

Survey Result:

 

Caer Drewyn (significant name change)         

Summit Height:  313.5m (converted to OSGM15, Leica GS15)

Summit Grid Reference:  SJ 09127 44416 (Leica GS15)

Bwlch Height:  222.7m (LIDAR)

Bwlch Grid Reference:  SJ 09770 45600 (LIDAR)

Drop:  90.8m (Leica GS15 summit and LIDAR bwlch) (Trichant addition)

Dominance:  28.96% (Leica GS15 summit and LIDAR bwlch)

 

 

For further details please consult the Trimble Survey Spreadsheet