Craig-y-Llyn Mawr Cairn is a prominent Bronze Age burial monument sited between two outcrop ridges. It is 8.0m in diameter and 0.6m high with a central depression around 1.5m in diameter. Reeds surrounding the cairn may suggest a possible ditch.

It is associated with the Lluest Uchaf Cairns and the stone row at SO00059832, and is part of a Bronze Age complex.

CPAT, Tir Gofal assessment, 2003
Cadw scheduling description 2004.

RCAHMW, 1 September 2010