According to Coflein there is an 'extensive series of rectangular stone houses, banks, field walls and enclosures of late medieval or early post medieval date but with a large enclosure and associated hut circle probably of prehistoric date' to be seen upon this ridge opposite Rhos-y-Gelynnen. Continuity of human habitation, then.
Coflein PRNs 16534-16540 inc. (1994 CE) (RSJ 2000) refer.
There is also an associated round cairn at SN91586139. Coflein, again:
'Site of round cairn, approx. 3m in diameter x 0.30m high. Slight hollow in central area with partial remains of robbed cist evident. Orientation E-W. Approx. 1m x 0.60m. W cist stone approx. 30cm thick (RSJ 2000)'