Earthfast Neolithic tomb, St David's Head

The famous cromlech near the tip of St David's Head, found in close proximity to an Iron Age fortified settlement site.  Strictly, this should be referred to as an earthfast tomb, since one end of the capstone has been levered up and then propped, but the other end still rests on the ground.  As usual, the guiding principle seems to have been economy of effort -- this big flattish stone was simply used where it was found.