Three Reader's Digest investigations take us into; Britain's subterranean caves, rivers, tunnels and bunkers from ancient times to the modern era; plus the shelters, secret weapons sites and hidden command centres of WW2; and the bunkers, citadels, and hidden nuclear command centres of Cold War Britain. Uncover the truth behind the secret escape tunnels linking Parliament, Downing Street and Buckingham Palace. Discover Edinburgh’s underground city of caves … hidden from prying eyes for centuries. Explore classified underground establishments built by the Government during World War II. Follow the cameras as these, and many more, mysteries are unravelled before your eyes!