Gop Cairn is a titanic cairn, 75-80m in diameter and 12m high, centrally disturbed.
It was explored in 1886-7 by a central shaft and drifts and faunal remains only were encountered.
It is traditionally a beacon site.
The Gop Cairn is Wales’ largest prehistoric monument and only surpassed in size by the prehistoric mounds of Silbury Hill and the Marlborough Mount in southern England. It commands a mighty vista from its elevated limestone plateau on the north coast of Wales, close to Prestatyn. A shaft sunk to its centre in the nineteenth century shed little light on its original purpose but it was clearly a place of enormous significance. The Gop Cave in the foreground has produced human skeletons, prehistoric flints and pottery. (Extract from the forthcoming 'Historic Wales from the Air', RCAHMW, 2012).