An earth and stone constructed dam associated with water management for ore processing at Clogwyn Coch copper mine (NPRN 33768). The dam measures 40m long by 8m wide and is up to 2m high. It has been breached in the middle and there is evidence of earthen footings for a launder running west from the dam towards a processing building (NPRN 505994). P.J. Schofield, OANorth, 30th January 2008