Corn Du Corn Du Corn Du is a mountain immediately to the southwest of Pen y Fan and the second highest peak in South Wales at 873 m (2,864 ft), situated in the Brecon Beacons National Park. The summit itself is marked by a well structured Bronze Age cairn with a central burial cist like that on nearby Pen y Fan. The two summits are visible from great distances owing to their height above the surrounding moorland, and are famous landmarks. The views from the peaks are also panoramic and very extensive, the Black Mountain and Fforest Fawr being especially obvious to
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