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 Gaer stone can be seen, as can those of a chevaux-de-frise. The entrance is to the west, and access can be gained from a car park, reached by the road from the village. Pen y Gaer Pen y Gaer (or Pen-y-gaer) is the location of a Bronze Age and Iron Age hillfort near the village of Llanbedr-y-Cennin in the Conwy valley, Wales. A natural defensive site, it had a long history of occupation, indicated by the complexity of the defences, which were amended over time. There are two Bronze Age cairns on the north-west slope, and extensive prehistoric and later field