This Bronze Age cist is one of only seven to have been documented on Exmoor, only two of which survive. It is lined with slate slabs, and a large 5ft square capstone still partially covers its top. The mound that would have surrounded it was dug into in 1820 for road stone :(
When the cist was disturbed a skeleton was found inside and this was generously (?) reinterred in the churchyard at nearby Treborough.
(info from the scheduled monument record on Magic / Somerset Historic Environment Record).