Great Canal Journeys

Brand new boaters Sheila and Gyles embark on their tour of London's waterways, starting on the upper reaches of the River Thames - a paradise of unspoiled nature, royal retreats and river regattas

Sheila Hancock and broadcaster Gyles Brandreth tackle their first manual lock and some terrifyingly tight turns, but find themselves relaxing into life at 4mph, and marvel at how secret histories reveal themselves. They visit the Royal Gunpowder Mills, which built its own canal system to transport volatile ammunition - vital to Britain's success in both world wars.