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 Fan mountain is used by the military as part of the selection process of the UK's Special Forces personnel. Three soldiers who died after collapsing in the field in July 2013 were believed to have been climbing the mountain (see "Fan Dance") while undergoing Special Air Service selection. The peak is a major objective in the Beacons Way, a long distance footpath which passes from east to west across the massif, and is open to all walkers. There is well made, evenly graded footpath from the Storey Arms on the A470, which is 1500 feet below, allowing for safe access during