Avoncliff Aqueduct (grid reference ST803599) carries the Kennet and Avon Canal over the River Avon and the Bath to Westbury railway, at Avoncliff in Wiltshire, England, about 1+1⁄2 miles (2.4 km) west of Bradford-on-Avon. It was built by John Rennie and chief engineer John Thomas, between 1797 and 1801. It is a Grade II* listed structure. During construction, stone from a local quarry was used which split when affected by frost. This caused buttresses to collapse and parts of the structure to need rebuilding. Eventually Bath stone from Bathampton Down was used to ensure greater stability.