Quinta Bridge No. 20 on the Llangollen Canal was the work of William Jessop and Thomas Telford and constructed between 1795 and 1801. The bridge has now been demolished, with the narrowing of the canal and stop-plank grooves indicative of its original location. The stop-plank grooves found on most canal narrowings were used to isolate sections of canal in case of a breach or for maintenance.

Louise Barker, RCAHMW, 14 September 2007.