A secret trapdoor discovered under the refridgerator in the kitchen of Peter and Helen Kroger's bungalow in Ruislip, March 1961. The Krogers, whose real names were Morris and Lona Cohen, had just been arrested for their involvement in the Portland Spy Ring, which leaked British military secrets to the Soviets. (Photo by Keystone/Hulton Archive/Getty Images)
Thousands of human remains, secret tunnels, secret hideouts and more. Really interesting stuff, man!