Trethevy Quoit

Like other portal structures of this type, Trethevy Quoit was originally covered by a mound. The remnants of this suggest a diameter of 6.5 m. The remaining seven stones and the 3.7 m long and 10.5-ton cover slab were inside the mound. At the upper end of the cover slab is a natural hole, which may have been used for astronomical observation. The group of horizontal stones is composed of a fallen back wall, two overlapping side wall stones, a front stone and a somewhat remote flanking stone. The special feature of Cornish portal graves is that by such stones sometimes a smaller partially closed area is created before the front end. Some stones have hole-like perforations as decoration. The…