Pen y Fan Pen y Fan Pen y Fan () is the highest peak in south Wales, situated in the Brecon Beacons National Park. At above sea-level, it is also the highest British peak south of Cadair Idris in Snowdonia. The twin summits of Pen y Fan and Corn Du at 873 m (2,864 ft) were formerly referred to as Cadair Arthur or 'Arthur's Seat'. The mountain and surrounding area are owned by the National Trust whose work parties attempt to combat the erosion caused by the passage of thousands of feet up and down this most popular of South Wales' peaks. The
Pen-y-Gwryd Plas y Brenin. The Old Miners' Track from the Snowdon copper mines are now part of the modern A4086 road between Pen-y-Gwryd and Pen-y-Pass. It continues northwards beyond Pen-y-Gwryd skirting Glyder Fach to Bwlch Tryfan and Dyffryn Ogwen. From Pen-y-Pass is the "PYG track", one of the many routes leading to the summit of Snowdon, its name is believed be derived from the initials ("P-y-G"). However, older maps show it as the "Pig track", a name derived from "Bwlch y Moch" (the Pigs' Gap). During Roman Britain, the Roman Army built a marching camp at the head of Dyffryn Mymbyr