Pairs of cairns with disturbed cists on Tarren Maerdy, on the ridge between the valleys of Rhondda Fawr (to the south) and Rhondda Fach (north).
Tarren Maerdy Cairn I (SS97959720)
A round cairn approximately 9m diameter and 0.7m high. In the centre is a cist defined on three sides by pitched slabs, with smaller packing stones behind, 1.25 x 0.5m and 0.7m deep. The cairn is set back from the brow of the hill, and therefore there is no view to the valley below, only the hill opposite.
Tarren Maerdy Cairn II (SS98049709)
A mound on the brow of a hill overlooking the Rhondda Fechan valley to the the north-east. It is approximately 4m in diameter and grass covered but with several boulders, including one pitched slab that possibly lined a cist.