Treasure Houses

This week's 'treasure houses' are Britain's canals. They reflect not only a lost form of transport, but a forgotten way of life. The narrowboats decorated with their roses and castles, were home for the 'boaties' and their wives and children.

Mark Curry sets off on his bike on the ancient pilgrims' route to Canterbury Cathedral. There, in the place where it happened, he tells the story of a row between a king and archbishop that ended in murder.

The most glittering and extravagant Treasure House London has ever seen was the Great Exhibition of 1851, which was masterminded by Prince Albert, the husband of Queen Victoria. Its 100,000 exhibits were seen by 6,059,195 people who consumed 102,337 bottles of soft drinks and 934,961 bath buns.

Today Mark Curry enters the maximum security barracks of the Intelligence Corps, hidden away in the Kent countryside, and finds a tiny museum which contains some of the most amazing spy stories ever told.