Bigsweir Bridge dates from 1825 and has a cast-iron span of 49 metres (160ft) on the Monmouth Turnpike. The bridge was cast in Merthyr Tydfil and it is probably the largest of the cast-iron bridges made at the south Wales ironworks. There is also a single-storey toll-house.

The site has been surveyed during aerial reconnaissance by the Royal Commission, the photographs are; RCAHMW AP94-CS 0447, RCAHMW AP945063/44-5. The monument has been de-scheduled but remains a Grade 2* listed structure of special architectural and historic interest.

Claire Parry, RCAHMW, 29 July 2011

Sources:
A Guide to the Industrial Archaeology of South East Wales, AIA, 2003
Cadw 20.05.2005