Trethevy Quoit is a well-preserved megalithic tomb located near St Cleer, Cornwall, United Kingdom. It is known locally as "the giant’s house".
Standing 9 feet (2.7 m) high, it consists of five standing stones capped by a large slab.
Excavations have shown that sites of this type were constructed in the early and middle Neolithic period between 3700 – 3300 B.C.
In 1999 there was some controversy regarding this site and others under the care of the English Heritage organisation. Members of a pressure group, the Revived Cornish Stannary Parliament, confiscated several signs bearing the English Heritage name.
Since this action, several of the smaller sites such as Dupath Well, The Hurlers (stone circles), Tregiffian Burial Chamber, St Breock Downs Monolith, King Doniert’s Stone, Trethevy Quoit and Carn Euny have been transferred to the care of the Cornwall Heritage Trust.