The Gop is a neolithic mound lying north of Trelawnyd in Flintshire, Wales, in the Clwydian Range. Oval in form, it is the second-largest such mound in Britain after Silbury Hill. Excavations have uncovered no burial chambers or other underground works. This may indicate that it was used as a look-out or hill fort; there is evidence that there was a considerable amount of stone on the top of hill. In the 17th century, its prominent position allowed a beacon to be placed there.
The mound lies on top of Gop Hill, a natural limestone outcrop, in the side of which are the Gop Caves.