This classic short walk is to the summit of Pen y Fan (886m, 2,864ft), the highest peak in South Wales and the Breacon Beacons National Park. It is very popular, especially on sunny weekends.
It involves a steep climb at the start to reach the ridge, but then continues fairly gentle on good paths for a short but very scenic section along a U-shaped ridge around a steep sided glacial valley, with stunning views over South Wales, and the Bristol Channel. From Pen y Fan you walk back to the second prominent top, Corn Du, with fantastic views down into the Cwm Llwch (valley) with its scenic lake. Form there descend on a different route along a less populated route involving a minor re-ascent to the car park by the Storey Arms Outdoor Centre on the A470 and make your way back along the road.
The entire route is over well maintained paths, the drops are steep only on 1 side, so none of it is scary, or needs a head for heights. Route finding (in clear weather) is easy. The summits are very exposed however, so this is a walk for a clear sunny day, with little wind or rain.
Pen y Fan is large glacial grassy mound with steep glacial sides, less rocky than the mountains of North Wales. It is the southern most mountain in Great Britain, about 3½ hours drive from London.
The Storey Arms (no longer a pub) car parks on the A470 can be reached by car, or regular bus (Cardiff - Merthyr - Storey Arms - Brecon).
This is the 'easy' ascent. For a walk along the full Brecon Beacons Horseshoe including all four of the table top peaks, see SWC Walk 278 Brecon Beacons Horsehoe, which starts from the Neuadd Reservoir access road (car only.