In 1992, residents of the rural Essex village of Kelvedon Hatch, England made a shocking discovery. With the Cold War at an end, the government decommissioned nuclear bunkers across the country and locals were startled to find that what they had believed for decades to be an underground reservoir was in fact a top-secret subterranean shelter.

Today, the 35,000 square-foot (3,251sqm) space still sprawls 80 feet (24m) beneath farmland belonging to Mike Parrish, a fifth-generation farmer and the grandson of Jim, who sold the land to the government back in the 1950s.

Click or scroll on to tour this intriguing government facility...