Rennie's engineering masterpiece to the west of Devizes, on the Kennet and Avon Canal is Caen Hill Locks. It consists of twenty nine locks, sixteen close together in a straight line ascending Caen Hill to overcome a rise of 237 feet (72 metres) from the Avon valley to the town of Devizes.

Large clay deposits found on Caen Hill when the locks were being built provided raw material for the brick making industry in the locality.

The locks were opened to commercial traffic in 1810. Nineteen year's later the canal company, who owned a nearby gasworks, put up gas lighting so the canal would be navigable 24 hours a day.

Left to die in 1951, they became the centre of restoration and the focal point of the reopening by Queen Elizabeth in 1990.