The 80ft (24m) high Gilwern Embankment carries the Brecknock and Abergavenny Canal (nprn 85124) over the Clydach Gorge; completed in 1797, it is one of the largest earthworks on a canal in Wales. The north end of the bank is pierced by a tunnel carrying the Glangrwyne section of the Clydach Railroad (nprn 276001).

RCAHMW, 01 Novembver 2007.