Mapping Mountains – Trimble Surveys – Mynyddoedd Duon

04.02.16  Mynydd Troed (SO 165 292) and Mynydd Llan-gors (SO 159 267)  

Mynydd Troed (SO 165 292)

The weather forecast was not at all promising with a mild and wet westerly blowing in, and as today was Ed’s 60^th birthday he wanted to get on something that had a little height to it.  Having seen the forecast I suggested a wander up to the Memorial on top of the 320m high Town Hill (SO 215 957), as this summit is positioned directly above where Ed lives and as he had visited its top many times, the thought did not exactly enthuse him.  Our first serious contender was Foel Goch in the Arennig, but this was quickly dispensed with in favour of heading south and keeping east away from the wetness of Eryri.  Hopefully the rain shadow to the east of higher ground would keep us relatively dry.  We chose a circuit of Mynydd Troed and Mynydd Llan-gors, hills I’d visited twice before, as both visits were a quick there and back from the high minor lane between the hills, a circuitous route held the prospect of venturing on to new ground, this is something that I always enjoy, and as Mynydd Troed has a map height just under 609.6m (2,000ft) we also had the prospect of getting Ed enthused with the Simms, the 600m P30 summits listed by Alan Dawson.

The weather as we drove south and approached Newtown was not good, with rain falling and grey clag enveloping the hills.  However, the further south we drove the clag disappeared, as did the rain, and by the time the elongated ridges of the Black Mountains appeared, albeit with their tops shrouded in cloud, the sky had brightened slightly and the distinctive profile of Mynydd Troed soon came in to view, its top just clear of cloud which skimmed its trig pillar.

We parked just beyond the farm of Blaenau-draw, having asked permission to do so.  Once boots and wellies were donned we walked back down the steep lane and up the other side to where a public footpath enters a field below the steep southerly slopes of Mynydd Troed.  Beyond the field a path amongst bracken headed up, by now sufficient height had been gained for the views down the Rhiangoll valley to open up with the lower re-claimed hill slopes pastoral green and set against the russet browns of the higher moorland slopes.

The view down the Rhiangoll valley

The narrow path headed straight up a lung busting slope and in time we crested the southerly ridge of Mynydd Troed, and still there was no rain, I thought this would arrive any minute as the forecast predicted that the westerly front was to deposit large quantities of the wet stuff on this part of Wales before a dry spell in the afternoon.  

Heading up the southern slopes of Mynydd Troed.  Photo: Edward Humphreys

As we joined the main path on the southerly ridge a pair of Red Kites flew, ever majestically, across the ridge, and the domed profile of Mynydd Troed bulged up in the distance, with the cloud bank just skimming its top.  Mynydd Troed is a fine hill, and would no doubt be festooned with more ascents if its 609m map height was just 1m higher.

The domed profile of Mynydd Troed

By the time we reached the trig pillar perched on the hill’s summit the cloud had descended.  We assessed the lay of land and decided that at least two points needed Trimbling, one approximately nine metres from the trig and the other about two metres from its base.

Gathering data on the summit area of Mynydd Troed

As the Trimble gathered its allotted five minutes of data from each point, Ed sheltered in a burrow reminiscent of a sink hole, whilst I scribbled all necessary details to include in the Trimble Survey Spreadsheet.  Once each point had been Trimbled, Ed posed for his customary birthday photo, holding six digits aloft in recognition of his 60^th birthday.

Happy 60th

During Trimble gathering the grey cloud had risen leaving us extensive views west, but by the time we left the summit the mist had descended again, but this was short lived as within a few minutes of leaving the trig we were out again, under the cloud bank, looking across at a tantalisingly brightening sky, and still there had been no rain.  Below us was the bwlch at the top of Cwm Sorgwm with Llyn Syfaddan (Llangors Lake) stretching silver like beside its patchwork of green fields.

Slithers of brightness on the horizon

Mynydd Llan-gors (SO 159 267)

The descent to the bwlch proved steep, and once the muddy path had been negotiated Ed waited patiently whilst I set the Trimble up on a convenient rock next to the minor road that passes over the bwlch, having measured the offset between it and the ground at the base of the rock beforehand.  The Trimble gathered another five minutes of data from what is the critical bwlch of Mynydd Llan-gors, our next and last hill of the day.

Gathering data at the bwlch area of Mynydd Llan-gors

All that remained was the steady ascent up a grassed path to the moorland summit of Mynydd Llan-gors and the descent back to the awaiting car.  The ascent gave us views of dramatic light on the lake below as shadowed surrounds were accentuated by a flash of sunlight brightening the dulled scene with a silver sheen and emerald fields.

Llyn Syfaddan (Llangors Lake)

The high point of Mynydd Llan-gors proved relatively easy to find and once the Trimble was placed on the summit and gathering data we waited patiently, chattering away beside the small pools that add interest to the moorland surroundings.

Gathering data on the summit area of Mynydd Llan-gors

As we left the summit on a path heading south-east toward the small bump of Pen Tir the cloud broke and sun poured down on the land.  This was welcome and rather surprising considering the earlier forecast.

And where rain was forecast, we had sunshine

The main path led us down to another, which headed toward the upper reaches of the paved lane where the car was parked.  To our north Mynydd Troed rose above the greenness of Cwm Sorgwm with its upper slopes brackened and heathered, a tranquil scene to view and be left with. 

LIDAR image of Mynydd Troed

LIDAR image of Mynydd Llan-gors

Survey Result:

Mynydd Troed

Summit Height:  608.5m (LIDAR) (Dewey status confirmed)

Summit Grid Reference:  SO 16575 29239 (LIDAR)

Bwlch Height:  323.2m (LIDAR)

Bwlch Grid Reference:  SO 17266 30029 (LIDAR)

Drop:  285.2m (LIDAR)

Dominance:  46.87% (LIDAR)

Mynydd Llan-gors

Summit Height:  515.0m (LIDAR)

Summit Grid Reference:  SO 15935 26701 (LIDAR)

Bwlch Height:  354.4m (LIDAR)

Bwlch Grid Reference:  SO 16068 28327 (LIDAR)

Drop:  160.6m (LIDAR)

Dominance:  31.18% (LIDAR)

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