but will certainly require the use of a map and compass in poor weather. The walk requires reasonable exertion. The main features of interest are the geomorphology, the birdlife and the superb views from the summits.
Start from the car park in a field at the end of the track from Pont Rhydybetws. There is a sign saying ‘NO MOTORS’. Continue along the main track into the valley of Cwm Llwch. After about 200m there is a wood on the left. Take the path to the right and follow up the hill into the field. The path goes past deciduous woodland with alder trees on the left and comes to a stile near a large oak tree. Continue in a north-westerly direction, reaching a second wooden stile with a yellow waymark arrow and then head towards a renovated farmhouse, turning right to bypass it on your left. Looking back, and to the south, you can see into Cwm Llwch valley. On the right is the bulk of Pen Milan over which this route climbs.
Skirting round the farm buildings cross a stile and the field ahead to a house in the trees (Clwydwaunhir). Cross a stile and walk down the left of the hawthorn hedge to a stile and stream. After crossing the stream, turn sharp left and follow the sign to Pen Milan.
Continue between holly trees, fording the stream again and follow the track ahead to the gate with a yellow waymark arrow and the National Trust sign to Pen Milan. This is where you cross the hill fence. Head due south along an indistinct path, aiming for the left side of the spur of land ahead and follow the land grooves up to the crest. A slightly sunken grassy track leads diagonally up the valley side to a path through gorse and bracken.
Llyn Cwm Llwch and Corn Du looking west from the summit of Pen y Fan
From here look up the valley to Pen y Fan on the left and Corn Du on the right. Far over to the east is Cefn Cwm Llwch ridge which will be your descent route. The route drops down this ridge to Twyn y Dyfnant on its left (N) edge.
Pass a group of hawthorn trees on the left and follow the old quarry track to a point where it swings sharply back to the right at the first zigzag. Continue south between small quarry spoils and keep on the main track to a flattened area of quarry debris. From here follow a walkers’ path to the cairn. From the cairn there are good views to the west to Craig Cerrig-glaisiad and Fan Nedd beyond.
Walk through peat haggs to a broader section of the ridge and so to Tommy Jones’ Obelisk. If the weather has deteriorated, a quick descent can be made from the obelisk down an obvious path to Llyn Cwm Llwch below. Otherwise, follow the ridge of Craig Cwm Llwch (SE) up the steep slope to the summit of Corn Due.
Ascending Corn Du from Bwlch Duwynt
The final 10m or so to the summit of Corn Du involves scrambling up the Plateau Beds but a stepped path leading diagonally right will avoid further damage to these loose crags. From the top of the stepped path cross left (E) to the summit of the crags overlooking Cwm Llwch.
From the cairn follow the crags (E) and descend into the col. The path swings around (ENE) and climbs along a broad track, well marked by cairns, to the trig point on the summit of Pen y Fan. For a description of the mountain and its panorama see ‘Geology and geomorphology of Pen y Fan,’ Walk 5 and ‘Pen y Fan vista,’ Walk 1. The summit of Pen y Fan is the site of a Bronze Age turf barrow that contained a rectangular stone cist within which was a cremated body and a copper-alloy object.
Scramble carefully down the crags due north of the summit cairn and follow the ridge of Cefn Cwm Llwch for about 2km. Take a small path which leaves the main track and bears left (N) towards the pile of stones at the disused quarry of Cwar Mawr (SN018 236). From here descend west-north-west (292°) to the spur of Twyn y Dyfnant and down the steep slope to the hill fence, keeping to the right of the coniferous forestry.
Cross the fence through a gate (SN009 241) and follow the line of trees diagonally down the slope to the right. At the end of the tree line turn sharp left and drop down to the field below. An indistinct path leads directly down the field after 80m. Head for the junction of hedges to the left and continue down the slope to the ford across the stream (SN007 244) and back to the start of the walk.
CORN DU
Corn Du is the site of a Bronze Age cairn, and the stones near the edge are the remains of an excavated funerary mound (also see ‘Cairn Pica,’ Walk 17). Corn Du is a fine vantage point with views to the west of the Fans and, in particular, of the finely sculpted headwall of Fan Fawr to the south-west. In the valley just below to the west is Blaen Taff Fawr, the headwaters of the River Taff. The south-east presents a quite different aspect down into the valley of Neuadd with its reservoirs and continuing view towards the South Wales coast in the distance.
WALK 3
Cwm Llwch Valley
| Start | Llwynbedw, Cwm Llwch (SO 006 246) |
| Distance | 6km (3.75 miles) |
| Total Ascent | 340m (1115ft) |
| Map | OL12 Western Area |
Cwm Llwch is a beautiful valley leading from the wooded plain south of Brecon and up into the U-shaped glacial upper reaches, climbing under the spectacular head wall of Corn Du. This walk is one for a more gentle frame of mind or perhaps when conditions suggest caution in venturing too high on the mountains. No great height is reached but the atmosphere of the Beacons is savoured and the scenery is typical of the northern valleys. An early start is rewarded by the eastern sun lighting not only the valley floor and waterfalls, but also the north-eastern face of Corn Du. The walk is safe in terms of route finding and requires average fitness. Features of interest include the geology and glaciology, the plant and birdlife, waterfalls, mountain scenery and local mythology.
Start at the end of the car park where there is a ‘NO MOTORS’ sign. The ford and the hillside on the left of the car park is your descent. Follow the track leading into the valley, coming soon to another ford across the same stream, Nant Cwm Llwch, with a wooden bridge on the left, through a second gate and then between wooded banks with fields on either side. From here there are good views into Cwm Llwch, with waterfalls in the foreground and a backdrop dominated by Corn Du straight ahead and Pen y Fan on the left.
GEOLOGY AND GEOMORPHOLOGY OF CWM LLWCH
Cwm Llwch was carved by glaciers during the last ice ages but its shape is different from many of the other glacial valleys in the Beacons. The upper section is relatively flat and contains a corrie lake, Llyn Cwm Llwch, but the gradient steepens in the middle section where the waterfalls are found, before the gradient eases again near Cwm-llwch Cottage. The reason for this may be a more resistant band of rock which is also responsible for the formation of the waterfalls. The classical U shape of glacial valleys has been further modified in the middle section by two streams which have cut down into the valley floor, leaving a ridge which the main footpath follows.
The track continues southwards between old stone walls and then detours around Cwm-llwch Cottage. Leave the cottage on your left and skirt around the right of the farmyard by crossing over two stiles. The wide open track ahead takes a direct line up a spur of land with stream courses on either side. However,
