The 6000-year-old Tinkinswood chamber consists of a wall of stones supporting a mammoth 7.4m-long, 36-tonne limestone capstone, thought to be the largest of its kind in Britain. It was once covered in an earth mound, but excavations in 1914 left one half of it open after pottery and the bones of 50 people were removed. A brick pillar was then added to prop up the capstone.
The entrance to the mound is approached by a curving avenue of stones, and other stones have been arranged nearby. The site was once known as Castell Carreg – the fairy castle.
Tinkinswood can be reached from St Nicholas village, accessed off the A48 some 6.5 miles southwest of Cardiff.