The lower 1.8km of the Glamorganshire Canal (nprn 34425), from the Customhouse Bridge (nprn 85400) to the Sea Lock (nprn 80401) was known as the sea pound. Opened in 1798 as an extension to the original Glamorganshire Canal, it provided access for ships up to 200 tons to wharves and other facilities. It was the last section of the Canal to close, on 05 December 1951, when the sand-sucker "Catherine Ethel" hit the sea lock gates and was washed out into the Bristol Channel, so draining the pound. The Canal towing path was on the eastern side and the Glamorganshire Canal Railway (nprn 91475) ran along the western side.
B.A.Malaws, RCAHMW, 08 June 2004.