It is the third highest mountain in Britain south of Snowdonia (after Pen y Fan and its near neighbour Corn Du).

Mudstone layers within these sandstones are more readily eroded and have given rise to the stepped appearance of parts of the mountain.

No rocks are exposed around its summit as this is covered by a thick layer of peat which has accumulated in the postglacial period, though is much reduced through erosion in recent decades.

Mountain bikers and horseriders can follow the bridleways which lead to the 617m high col south of Pen Trumau but have no legal access to the hill itself.

The paths approaching from the north and west have been repaired and improved by the Brecon Beacons National Park Authority, most recently through the Black Mountains Land Use Partnership in recent years, having previously become particularly damaged by use.