Cross the road and go through the gate next to the telephone box. The large building to your right is the Storey Arms, now an outdoor education centre but once a wayside inn on the coaching road between Brecon and South Wales. The original road can be seen forking off to your left, forming a section of the Taff Trail, a long distance route between Cardiff and Brecon. Follow a clear path up the hillside, leaving the plantation behind and crossing the open moorland of the southern flanks of Y Gyrn – a rounded summit to your left. You’ll soon gain the ridge and go through a kissing gate to drop easily down to the infant Taf Fawr – a pleasant and sheltered spot, ideal for a break before you reach the exposed hilltops above. The way ahead is clear, with a manmade track climbing steeply up the hillside opposite. Follow this, keeping straight ahead at a fork near the top, until it reaches the escarpment edge above the magnificent valley of Cwm Llwch. Below you’ll see the glacierformed lake of Llyn Cwm Llwch, and above this the steep head wall that unites the twin peaks./p>

Turn right to follow the clear path up towards the rocky ramparts of Corn Du. The path slips easily around the craggy outcrops and leads you up to the huge cairn on top of the broad summit plateau. The views down the valley are awesome, but take care as some of the summit rocks pretty much overhang the chasm below

The way to Pen y Fan is obvious from here. Drop into the shallow saddle to the east and continue easily on to the summit. This opens up a whole new vista, with the narrow ridge of Cefn Cwm Llwch acting as the dividing wall for the remote Cwm Sere, to the right as you look out.

The northeast face of the mountain is particularly precipitous so take care near the edges. The most enjoyable way to begin your descent is to retrace your steps across Corn Du (Point 3) and turn left to Bwlch Duwynt, the obvious saddle between the summit and the long ridge that runs south. Alternatively, a good path runs below Corn Du, allowing easy passage with no extra height gain. To locate this, drop back into the saddle you’ve just crossed and fork left, beneath the grassy slope that leads to the summit. The views from this section are to the south, over the two currently drained, Neuadd reservoirs. Bwlch Duwynt represents a fairly major junction of paths, but you’ll easily locate the main track that forks downhill to your right, away from Corn Du. Again, sections of this track have been laid in stone to slow the erosion caused by thousands of walkers’ feet. Follow the track easily down for just over a mile (1.6km) until you see the Taf Fawr river to your right-hand side. A short diversion to your right near the bottom will reveal a great, rocky picnic spot, situated above a small waterfall. Cross the bridge over the river and go through the kissing gate into the main car park.

Turn right into the car park and follow it to its end where a broad dirt track takes over. Continue along the side of the plantation and cross the road to return to the start.