This ruined cairn seems to have an interesting location, surrounded on its west, south and eastern sides by water – many streams join together in its vicinity. The Mabinogion notes say: “This spot is still called Ynys Bronwen, or the Islet of Bronwen, which is a remarkable confirmation of the genuineness of this discovery.”
Jennifer Westwood in ‘Albion’ has details of its excavation. Originally a standing stone stood alone at the site, and some time after a cairn ring was built around it. A couple of small cists were also found; these had been used for more than one ‘batch’ of Bronze age cremations. The mound which covered it was never particularly high. Pollen analysis showed that when this was built the site was in a meadow covered with buttercups.