The Gop (Welsh: Coparleni, also known as Gop Cairn or Gop-y-Goleuni) is a Neolithic monument lying within the Clwydian Range, northwest of Trelawnyd, in Flintshire, Wales.
Oval in form, it is the second-largest Neolithic mound in Britain after Silbury Hill, in Wiltshire.
Sitting on top of Gop Hill (823 feet), a natural outcrop of Carboniferous Limestone, the cairn mound is 75-80m in diameter and 12m high.
[1] There is evidence that there was a considerable amount of stone on the top of hill, but excavations have not uncovered a burial chamber or other underground works, which may indicate that it was used as a look-out or hill fort.
However prehistoric animal remains were found both in the mound itself and in Gop Cave below.