Great secrecy surrounded the construction of Kelvedon Hatch Nuclear Bunker. For many decades, the general public knew nothing about its existence. Throughout the Cold War, it had a constant small military presence, to ensure that it could be used immediately if there was a nuclear attack on Britain.

Mock military operations were carried out occasionally to check that we were ready and could cope with a nuclear war. The bunker lies 100ft below the ground, protected by a specially constructed structure that can withstand a nuclear explosion and subsequent radioactive fallout.

It is only accessible through the farmhouse above ground – was never actually used as the farmer's house. This was a deliberate disguise to hide the secret bunker beneath it. If anyone accidentally stumbled across it, they would not suspect that a bunker lay deep below. It was a very clever way of keeping its identity secret, especially from the Russians.