An atmospheric walk on the edge of the central Brecon Beacons, crossing the cultural divide between mid and south Wales along an old tramroad linking the canal at Talybont on Usk to once important quarries near Trefil. The return journey involves a short stretch of cross-country walking followed by a scenic saunter along an ancient track. There are several alternative routes allowing you to make the walk shorter or longer – all of which are mentioned in the text.