Several tumuli at one time existed on Selattyn Hill, and there are still the remains of one at “Orsedd Wen”, which has been opened and which tradition connected with Gwen, the son of Llywarch Hen, who is said to have been slain on the adjacent Morlas, near “Prees Gwyn”.
From a review of the “History of Selattyn Parish” in Archaeologia Cambrensis, Jan. 1898.
But I suspect this is no local tale at all but comes from a highly imaginative article in the same journal, back in 1851. The author seems desperate to prove the site contains the son of Llywarch Hen, using various tiny ambiguous snippets from old manuscripts, but he basicially ransacks the cairn – the poor occupant is not treated with any dignity. It’s a strange combination of attitudes and if I met thedigger/author, W Wynne Foulkes, I think I’d give him a piece of my mind.