Fred Dibnah's search to discover how the work of the builders and engineers of the past helped to shape Britain brings him close to his home town of Bolton, where the mid-18th century saw the building of the first canals and the arrival of the first civil engineers. He travels to Worsley in Lancashire to see where it all started - the labyrinth of 52 miles of underground waterways that carried coal from the Duke of Bridgewater's mines to the canal. Back in his garden, he shows us how the early canal engineers actually went about digging the cut for a canal and making it watertight. He takes a canal boat on the 127-mile-long Leeds-Liverpool Canal, and demonstrates the back-breaking labour and enginering skills that went into building the tunnel that takes it under the highest point on his route.

• Fred Dibnah