Radiocarbon dating has given a date of 1,900 BC, with finds of flint tools and a double kerb of large stones, some of them weighing over a tonne each.
Mae dyddio radiocarbon wedi rhoi dyddiad o 1,900 CC, wedi iddynt ddarganfod offer fflint ac ymylfaen ddwbl o gerrig mawr, rhai ohonynt yn pwyso dros dunnell yr un.