Former double lock, with tailbridge, on the Abercynon flight of the Glamorganshire Canal (nprn 34425), which consisted of sixteen locks (two single and seven doubles) in 1.6km or 1mile, giving a rise towards Merthyr of 63m or 207feet. No remains of Lock y Waun are now visible.
Site visited B.A.Malaws, RCAHMW, June 1979.