The Secret Nuclear Bunker at Kelvedon Hatch, in Essex, England, is a large underground bunker used during the Cold War as a Regional Government Headquarters. Since being decommissioned in 1992, the bunker has been open to the public as a tourist attraction, with a museum focusing on its Cold War history.

Built in 1952–53 as part of ROTOR, a program to improve and harden Britain’s air defense network, the bunker was a hardened Sector Operations Center (SOC), meant to provide command and control of the London Sector of the RAF Fighter Command.

The bunker was able to hold hundreds of military and civilian personnel, and could sustain them for up to three months. In the event of a nuclear strike, the RGS / RGHQs etc would be tasked to organize the survival of the population and continue government operations. The area they chose had to be off the main road, behind fields and forests, to prevent civilians from finding it.

The bunker is built 125 feet (38 meters) underground, and the entrance is through an ordinary looking ‘bungalow’ (a standard ROTOR ‘Guard House’) set amongst trees. Once in the bungalow, a 100-yard-long tunnel leads down to the bunker’s lowest floor. Above are two more floors, the “hill” which covers it, and a radio mast.

The bunker has air conditioning and heating, its own water supply, and generators, and was equipped with many types of radio equipment, protected telecommunications, teleprinter networks, and various military systems.

The bunker was eventually decommissioned in the early 1990s after the fall of the Soviet Union, when the nuclear threat was seen to have diminished. The bunker was turned into a museum and the land was sold back to the family that had originally owned it in the 1950s. Locals now appreciate the irony of the many brown tourist signs, clearly directing people to the “Secret Nuclear Bunker” in the area.