Pen y Fan same noun "ban", in its plural form "bannau", is found in the Welsh name for the Brecon Beacons: "Bannau Brycheiniog". There is no one standard translation of "Pen y Fan", but 'the mountain's peak' or 'the beacon's summit' are both possible translations. Pen y Fan is formed from various units of the Old Red Sandstone which were laid down during the Devonian period. The lower slopes of the mountain are formed from the sandstones and mudstones of the Senni Formation whilst the upper slopes are formed from those of the Brownstones Formation. The very summit, like that of neighbouring Corn
Pen y Fan the Welsh Government. Toilet facilities are available at the site. A footpath connects the Storey Arms centre, bus stops and the Pont ar Daf car park to the path leading to Corn Du and Pen y Fan. The summit lies on a ridge stretching from Talybont Reservoir in the east, to the A470. About to the south-west lies the subsidiary top of Corn Du, beyond which the terrain drops at a moderate angle to the subsidiary top of Y Gyrn then more steeply to the Storey Arms on the A470. To the east, the ridge drops steeply to the col