Known to the British and US spies as “Object 1180” these two structures were built in 1985 – at the height of the Cold War. As the threat of a nuclear strike from either side seemed more than likely, high-ranking officers needed somewhere to orchestrate their retaliation and prepare for a second strike. As a result, the cylinders were built with thick walls to withstand a direct nuclear hit and an entire city was concealed below with shops, hospitals and a vast amount of supplies to provide the generals with everything they needed.