The sea lock of the Glamorganshire Canal (nprn 34425) dates from 1798. The walls were built of finely jointed ashlar stone blocks, with nineteenth and twentieth century repairs, curving outwards at the sea end. When visited in May 1977, the seaward gate had been replaced by a concrete wall and the rest of the lock filled in and grassed over. Steps were noted in the west wall leading down to the water and five cast iron mooring bollards were upstanding. A swingbridge carried Ferry Road over the middle of the lock, but was demolished before 1900. The whole site has been destroyed by the Cardiff Bay approach road.
B.A.Malaws, RCAHMW, 11 November 2009.