Pen-y-Fan and Cribyn from Cwm Gwdi

The Beacons via the back door.

This energetic walk gets you to a well-known spot – the summit of Pen-y-Fan – on one of the less familiar routes. We think it’s possibly the most dramatic way to get to the top.


Need to know

Length: 7½ miles (12km)
Time: Around 3–4 hours
Start and finish: Cwm Gwdi car park (in lanes 2 miles/3.2km south of Brecon)
OS map ref: SO 024247 
OS map: OL12 Explorer (1:25 000 series)
Facilities: Car park 

Along the way

Cwm Llwch
The deep hollow beneath Corn Du is one off the Brecon Beacons’ many textbook geological features. This cwm, or cirque, was scooped out by grinding glaciers during the last Ice Age. Its glacial lake is another classic Ice Age feature. In recognition of its outstanding geological heritage, the western half of the Brecon Beacons National Park (which includes the area covered by this walk) was designated a European Geopark in 2005.
At 886m it’s the highest mountain in South Wales and Southern Britain. Its distinctive flat top, so characteristic of the Beacons, is caused by the protective Plateau Beds that are even tougher than the underlying Brownstones, a sub-division of the Old Red Sandstone that forms the backbone of the National Park. The rocks of the Beacons once lay at sea level. Look closely near the summit and you can see fossilised sand ripples, the mountaintop remains of an ancient beach. Pen-y-Fan has had a special significance and allure for millennia: its summit is marked by the remains of a Bronze Age burial cairn.
Corn Du
At 873m it’s a mere 13m lower than Pen-y-Fan (the views are just as sensational).
The 795m summit of Cribyn is, like Pen-y-Fan, marked by the remains of a Bronze Age burial cairn.
‘The Gap’ and Roman road
Bwlch ar y Fan is better known as ‘The Gap’ – and, if somewhat prosaically, it’s well named. At 559m it’s a pronounced break in the mountains (you won’t want to picnic here when the wind funnels through) and an obvious north–south route through the central Beacons.  The unsurfaced road that cuts through The Gap may well be Roman in origin.

For a full route description, please click here.