“In Wiltshire, England, 120ft below the surface, lies Burlington, aka Cold War City – the 35 acre subterranean complex built in the 1950s to house the Conservative prime minister Harold Macmillan’s cabinet and 4,000 civil servants in the event of a Soviet nuclear attack “It was equipped with the second largest telephone exchange in Britain and a BBC studio from where the prime minister could make broadcasts to what remained of the nation. A system of underground power stations would have provided electricity to the 100,000 lamps that lit its streets and guided the way to a pub modelled on the Red Lion in Whitehall. “A spur railway was built inside a tunnel on the main London to Bristol line, linking it to the bunker. It was meant as an escape route for the royal family to flee London in the event of an attack. “The bunker’s very existence was meant to be top secret until it was decommissioned in 2004. Inside, it is like stepping back 50 years. Hundreds of swivel chairs delivered in 1959 are still unpacked. There are boxes of government-issue glass ashtrays, lavatory brushes and civil service tea sets. Pictures of the Queen, Princess Margaret and Grace Kelly are pinned to the walls.”