Hollow Demon Oak

A tree known as Derwen Ceubren yr Ellyl (hollow tree of the demons/spirits) used to stand in Nannau Park and it had a reputation of being haunted and evil, for this is the tree in which Owain Glyndwr was, according to legend, supposed to have hidden the body of his cousin Hywel Sele, 8th Lord of Nannau after he had killed him in 1404.