trethevy quoit is sited on a promontory overlooking the confluence of streams which flow southwards to become the river seaton; the northern skyline is dominated by caradon hill and granite massif of minions moor
four large overlapping granite slabs set upright form the sides of the chamber with lateral stones at front and back. the back stone is leaning inwards, and the massive capstone which is supported by these uprights. it is not clear whether this was a feature of the original design of the monument or the result of a partial collapse or slippage. a round hole has been drilled through the top corner of the capstone and may have used to capture a part of the heavens. a small antechamber was formed at the front of the monument but only one of the two original upright stones remains. a rectangular cut-out at the side of the upright stone that forms the front of the main chamber may have been an original entrance – although no other cornish site has such a feature. the quoit is surrounded by a stony mound or cairn which would probably have been more impressive than it is today, though it is thought unlikely that the quoit would ever have been completely covered. see illustration.
recent excavations showed that this type of megalith was erected in the neolithic period between 3700-3500 bc and such megaliths were used over a long period of time as community graves. [barnett]
below: plan and conjectural reconstruction of trethevy quoit. redrawn rh from barnett and others