The reference to "Ednyfed's Castle" is related to Ednyfed Fychan (c. 1170–1246), a powerful Welsh nobleman, warrior, and ancestor of the Tudor dynasty. He was the distain (seneschal or chief minister) to the Princes of Gwynedd, Llywelyn the Great and his son, Dafydd ap Llywelyn.
Ednyfed's vast landholdings and manors were scattered across North Wales, and he is associated with at least two sites where a defensible residence or "castle" of a Welsh lord would have stood.
What it was: This site, on Bryn Euryn hill, is traditionally believed to be the location of one of Ednyfed's main manors (or llys, a native Welsh court).
The "Castle": The structure associated with Ednyfed would have been an earlier, probably timber, defensive structure like a motte and bailey castle, typical for a Welsh lord of the 13th century.
Current Site: Today, the site is dominated by the ruins of the later 15th-century fortified manor house known as Llys Euryn, which was built on the same spot.