Underground bunkers are among the world's most fascinating structures. They're designed to protect people from the worst effects of atomic warfare and global annihilation. Here is an incredible look inside some of the most secure locations on the planet.
The German Government Bunker (Regierungsbunker), 16 miles (25 km) south of Bonn, Germany
Officially named Emergency Seat of the Federal Constitutional Organs for the State of Crisis or State of Defence to Maintain their Ability to Function, (Ausweichsitz der Verfassungsorgane des Bundes im Krisen- und Verteidigungsfall zur Wahrung von deren Funktionstüchtigkeit, or AdVB) and built between 1960 and 1972.
Burlington Cold War City (but known as Stockwell, Subterfuge, Turnstile and Site 3), Corsham, Wiltshire, United Kingdom
This is the former emergency relocation site for the British government in the event of nuclear attack.
Coffee machine in the main canteen, of course.
The BBC's underground broadcasting studios for the Prime Minister to address the nation.
A wooden telephone switchboard from the 1950s
This butterfly valve could be closed to prevent nuclear fallout or chemical contamination from entering the ventilation system.
The storage area, containing everything from glass ashtrays to stationary and unused telephones.
This telephone exchange was maintainted by British Telecom until the mid-80s.
The Prime Minister's private bathroom
The Greenbrier (or the Project Greek Island, Project Casper or Project X), the former U.S. Government Relocation Facility, White Sulphur Springs, West Virginia
This emergency shelter under the Greenbrier Hotel was never actually used, and its existence was revealed thirty years after its completion, in 1992 by Ted Gup of The Washington Post.
Emergency Government Headquarters, built for the Government of Canada
These bunkers are called Diefenbunkers, after the Prime Minister of the day, John Diefenbaker.
The Prime Minister's office
At the subterranean dentist's office.
The doctor's office
Underground Project 131, Hubei province, China
This system of tunnels was constructed in the 1960s and 1970s for the Chinese military command headquarters in a nuclear war. It was never fully completed, and now it functions as a museum.
"Visitors not allowed beyond this point."
(via Wikimedia Commons)
Cheyenne Mountain nuclear bunker (NORAD), near Colorado Springs, Colorado
The complex was designed to withstand a 30 megaton nuclear explosion within 1.2 mi (1.9 km). It was built between 1961 and 1966, and used for forty years.
Bonus: A bunker, used during the two World Wars, somewhere in France
Abandoned since the 1970s.