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-cae, Wrexham the Primitive Methodist chapel in Copperas. Coal was extracted from pits at Plas Bennion, Wynn Hall, Afon Eitha, Cristionydd, Groes and Plas Isaf; zinc was worked at Copperas. The area descending towards Acrefair was known as "The Delph", it was served by extensions of the Ruabon Brook Tramway but these were mostly defunct by the mid-20th century. Most inhabitants find employment outside the village in Wrexham with only a few local shops or public buildings providing jobs. "Dee Valley Water" operates two reservoirs in Pen-y-cae: "Pen-y-cae Upper" and "Pen-y-cae Lower". Wright & Son, ran a bus service from Pen-y-cae to