Corn Du the last ice age by ice scouring out hollows below the peaks, the water being partly dammed by moraines of rock debris carried down by ice action subsequent to plucking and frost shattering. 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
Pen-y-ghent summit. The more direct route that traverses the southern 'nose' of the hill is the route usually taken by those attempting the Yorkshire Three Peaks Challenge, as the walk is usually (but not exclusively) done in an anti-clockwise direction starting and finishing in Horton in Ribblesdale. The other main hillwalking route on the hill heads north from the summit to reach Plover Hill before descending to join Foxup Road, a bridleway at the head of Littondale. Pen-y-ghent is one of the mountains on the Yorkshire Three Peaks route. Pen-y-Ghent is made up of a millstone grit top sat upon a