Visited this area last week and was struck by this site. The structure in the first two photos seemed to me far too 'neat and tidy', somehow, to be authentic, and it is not marked on the 1:25 000 map as an antiquity although there is enough room so to do. The 'kerbstones' do not appear to be sunk into the ground at all, which is odd (pab's photos show this). All rather strange, but what do I know. The 'true' Mynydd Egryn settlement is a couple of hundred yards further uphill, as shown in the 4th photo, right next to Hengwm Ring Cairn.
Something is not right. This message is just to keep things from messing up down the road