The ruins of medieval hall house at Cefn-y-Fan include the service wing and annex.

'Ruins reduced to the lowest courses, probably of 'y' llys ynghefn y fann' of Ieuan ap Maredudd ap Hywel, which with his other house of 'Keselgyfarch' is said to have been burnt by Owain Glyndwr in 1403. Excavations in 1953 [by RCAHMW] confirmed that identification on the whole, although there was no evidence of conflagration.' (Excerpt from Caernarvonshire Inventory, Central, site 890, page 69).

T. Driver, RCAHMW, 28 Feb 2008.