A former double lock with a tailbridge (nprn 85415) on the Abercynon flight of the Glamorganshire Canal (nprn 34425), which consisted of sixteen locks in 1.6km, giving a rise towards Merthyr of 63m. No remains of Lock yr Odyn are now visible. Dating from 1799, the upper canal feeder (nprn 407030) supplied water to a point just below the lock at approximately ST 0857 9517. The limekiln, from which the lock takes its name, lies immediately to the west of the upper lock chamber; Ordnance Survey map evidence suggests that the kiln went out of use between 1900 and 1919.
B.A.Malaws, RCAHMW, 21 November 2007.