Standing at 713m and the highest summit on the Ffwddog Ridge Rhos Dirion is not that impressive if approached from the North, East or South but from the West and the town of Hay on Wye this summit forms part of the Northern escarpment where it holds the centre stage of the Black Mountains
The Northern or more accurately north west face of the Black Mountains tells the story of the hills as the great northern glacial of the last ice age met the Old Red Sandstone of the Black Mountains and gradually devoured it leaving behind a steep cliff face which is very unlike the western face which has a more mellow flowing decent in to the flood plains of the river Usk.
By far the best route to take to visit Rhos Dirion is the gradual accent from the iron age hill fort of Twyn y Gaer just above Cwmyoy with the river Honddu on your right and Grwyne Fawr river on your left. Walking the ridge you will be walking in the footsteps of Mesolithic hunters and Iron age shepherds and crossing the scene of a murder now marked by the Stone of Revenge. This route is covered with a downloadable g.p.s map on the routes page.