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 Garn Pen Pumlumon Arwystli. 21 km to the west is the town of Aberystwyth; Drygarn Fawr lies 20 km to the SSE . Pen y Garn Pen y Garn is a mountain in the Cambrian Mountains, Mid Wales standing at 611 metres above sea level. Pen y Garn tops a 500–600 m high plateau, situated on which is the controversial Cefn Coch wind farm. The summit contains a very large shelter cairn hollowed out from the remains of an ancient burial cairn. The summit also has a trig point. The wind turbines are very near the summit. To the north some