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 Llithrig y Wrach underfoot, or because of the resemblance of its pointed profile to an archetypal witch's hat. It is an outlier of the Carneddau, the higher peaks of which can be reached from Pen Llithrig y Wrach via Pen yr Helgi Du. On its eastern side, the mountain slopes steeply down to Llyn Cowlyd. It may be climbed from the southern side, from Capel Curig or the A5, or from the north-east, from Dolgarrog or Tal-y-bont in the Conwy valley. It is quite prominent when viewed from the north near Llandudno. Pen Llithrig y Wrach Pen Llithrig y Wrach is a mountain