From Rhayader take the B4518 to St Harmon but turn almost immediately left, towards Nantserth and Tynshimley farms, passing a mind control, er I mean radio mast on your right. The road up there is single file, watch out for car chasing dogs, turn right when you get to a crossroads, well, a road crossing a rough dirt track, follow the track as far as you want, there are plenty of opportunistic parking places.
Arthur and me left the car half way up the east/west track, out of view of either farm houses, I don't think neither are farms though.
Through the gate at the bottom of the track and the footpath takes you right past the barrow. Another gate climbed and i'm in the barrow field.
It is a big one, comparable with Barrow 4 at Staylittle, I didn't know that at the time though because I hadn't been there yet.
About two meters tall and a good twenty odd across, and fair covered in thistles. The barrow is pretty spread out, one wonders if all spread barrows are ploughed down or were they ever designed that way. Moel Hywel at over five hundred meters high dominates the near surroundings. Standing on top of the barrow the south west view opens up as far as Esgair Penygarreg, itself cairn topped, but then all the hills round there are. They're on the list but not today though, another time.