Cities of the Underworld S01E07 - London's Lost Cities: London, England

For thousands of years, London has been among the most influential cities in the world. Below the busy streets and marketplaces, another city hides--a city of Roman baths, secret crypts, lost rivers, indestructible bunkers that could hold up to 8,000 people, and Winston Churchill's hidden war-rooms; host Eric Geller.