of the other Beacons valleys and ridges, Fan y Big and the Black Mountains beyond.
Descend (NNE) following the narrow prow of Cribyn. The steep descent down the nose of Cribyn can be exciting in snow and ice conditions and may well require crampons and an ice axe. Stop now and again to enjoy the views – look over into the adjacent valley of Cwm Cynwyn through which runs the Roman Road (see Walk 11) up to Bwlch ar y Fan between Cribyn and Fan y Big.
The return route heads down Bryn Teg (NNE) on a wide grassy track to a gate past a sign reading ‘Entry to National Trust Land’ (Bannau Brycheiniog – The Brecon Beacons). Follow the stony track, part of the Roman Road, which leads down to a crossroads where you take the road ahead. This leads back to the stone bridge from where you started.
Extension
Climb W along Craig Cwm Sere to the summit of Pen y Fan. The final ascent of Pen y Fan is badly eroded but the National Trust has built a zigzag path out of the Brownstones to reduce further damage. Now descend back to the unnamed col between Pen y Fan and Cribyn and rejoin Walk 5.
Alternative route
Traverse around the shoulder of Cribyn along a sheep track. This is the most exciting mountain route in the Beacons, the narrowness of the path and the steep drops giving the walker a real taste of exposure. Remember that great care must be exercised here in winter conditions where crampons and an ice axe may well be the order of the day. Look back now and again at the north-east face of Pen y Fan which dominates the skyline, making this one of the finest viewpoints in the Beacons. The final part of this traverse affords grand views of Cwm Sere and across Allt Ddu to the town of Brecon on the left. (See Walk 6 for a description of the flora of the north-west face of Cribyn). Now rejoin Walk 5 at the start of Bryn Teg.
WALK 6
Cwm Sere Ridge
| Start | Pont y Caniedydd (SO 039 244) |
| Distance | 10km (6 miles) |
| Total Ascent | 560m (1841ft) |
| Map | OL12 Western Area |
This is one of the classic ridge walks in the Beacons. The route climbs the ridge on the east side of the valley and includes ascents of Cribyn and the highest peak in the Beacons, Pen y Fan. Descent is via Cefn Cwm Llwch, the ridge on the western border of the valley. The ascents and descents in the upper reaches are steep and good walking fitness is essential. Interesting features include a nature reserve, the mountain geology and excellent views of all the high peaks and the valleys associated with them.
From the car parking area at Pont y Caniedydd turn south-east, cross over the bridge and up the lane ahead. On the right of the road into the valley of Cwm Sere is a woodland nature reserve managed by the Brecknock Wildlife Trust (see Walk 7).
Nant Sere drains the vast cauldron formed by the headwalls of Cribyn and Pen y Fan. Water avens and mossy saxifrage grow on the banks of this mountain stream which then flows on through ash, alder and birch woodland. Cwm Sere is extremely rich in flora and fauna with over 200 species of flowering plants and ferns, abundant fungi, birds and insects, at least two of which are rare arctic-alpine species.
Continue past the turning on the left to Bailea Farm, and follow the road up the hill to where it swings sharp left and through a gate. Ignore this turning and follow the stony track, the old Roman Road (see Walk 11), for 250m straight ahead to a gate in the hill fence, on the far side of which is a National Trust sign for Cwm Cynwyn.
On the left is the ridge of Cefn Cyff which leads down from Fan y Big and straight ahead is the ridge of Bryn Teg which you are about to ascend to the summit of Cribyn. On the right is Cefn Cwm Llwch which leads down from Pen y Fan and this will be your descent route.
Continuing from this point at the hill fence, ignore the stony track which goes off to the left and head straight for the ridge ahead of you. After a concentrated pull up the beginning of this ridge you arrive at a cairn. The ridge ascends in three main steps and after the second major climb you arrive at a level section marked by a second cairn. The final step is the ascent of the prow of Cribyn. The alternative route to Pen y Fan leaves from here.
Pen y Fan from Bryn Teg
The step in the middle of the ridge has formed due to the underlying geology. This step is known as a secondary scarp and results from a change from Brownstones to Senni Beds.
Climb the narrow path to the summit of Cribyn, then descend west along a distinct eroded path to the col. To the south is the Neuadd Valley where two small reservoirs dam the Blaen Taf Fechan, which is fed by surface run-off and ground-water collected in this basin.
From the col, climb steadily (W) following the line of Craig Cwm Sere to the summit of Pen y Fan. The final ascent to the summit of Pen y Fan is up a very stony area and The National Trust has built a zigzag path up this face to the top.
Walk across the flat surface of Pen y Fan, which is also badly eroded, to the trig point. This can be found in bad visibility by carefully following the north-east crag line. The trig point is at the end of this to the left. The north-east face is very steep and care must be taken not to stray too near the edge, especially in strong south-westerly winds or when corniced in winter.
Leave the summit of Pen y Fan by carefully scrambling (NNE) down the exposed Plateau Beds. The rocks can be slippery but the route drops quickly to the fine ridge of Cefn Cwm Llwch.
Follow the path along the flat section of the ridge, leaving it when it drops gradually to the valley of Cwm Gwdi. Keep to the eastern edge of the ridge, following a path through some boggy areas with mainly heather, past the disused quarries and onwards to Allt Ddu.
From the pools on the summit of Allt Ddu drop down past the stones of the quarry towards the Plas-y-gaer settlement. Just on the edge of this hill there is a distinctive furrow in the hillside which is an old quarry path. Continue down this path (marked with a dotted line on the map) towards the settlement, descending the front of the ridge. The descent of this ridge provides a good view of the settlement with the earth bank being now planted with a line of large trees.
Blaen Taf Fechan and the Upper Neaudd Reservoir
At the bottom of the slope turn left in front of the settlement. As you come round the corner of the settlement follow the path diagonally down to the left, arriving at a stone wall. There is a finger post and gate. A track leads to the farm (Plas-y-gaer). At the farm turn left through a gate and right into a field at the blue waymark post.
From here head across the field to a line of pylons reached through a gap in the trees. Turn right at a line of trees and walk up to a gate and stile in the right corner of the field. After crossing the stile, descend a shallow valley to another stile which you will see in the field about 60m in front of you. Follow the wire fence on the right-hand side downslope to the derelict buildings. Walk to the left of the farm buildings to a stile in a fence and onto a track. At the end of the farm track is a gate beyond which is a tarmac road. Turn right on the road and down the hill to the start at Pont y Caniedydd.
Alternative route
Follow the Cribyn face path off to your right leading to the col between Cribyn and Pen y Fan.
The further you travel, the steeper the cliff becomes with the Brownstones becoming more prominent up to your left. These are responsible