Group of three cairns on Mynydd Ty'n-tyle, on the ridge between the valleys of Rhondda Fawr and Rhondda Fach. Coflein descriptions (north-south):
Cefn-y-Rhondda Cairn III (SS99189644)
A centrally depressed stony mound, 7.0m in diameter and 0.5m high.
Cefn-y-Rhondda Cairn II (SS99299631)
A denuded probable round cairn, although part of the 'kerb' on the west side appears to be bedrock. It is approximately 11m in diameter and up to 0.7m high on the west side and has an exposed slab in the centre. Set on a natural plateau, it has views across the other mountain tops but not to the valleys.
Cefn-y-Rhondda Cairn I (SS99279629)
A round cairn, 5m in diameter and up to 0.5m high. It is grass covered and in the centre is a 1m square depression with a possible cist wall exposed. Set on a natural plateau, it has views across the other mountain tops but not to the valleys.