I figure it's worth firing a link over to this article on one of the last pieces of the Cold War winding down - BT closing down it's operations with the government for a Cold War telecom system, including the UK's second biggest exchange.

BT employees worked together with the Cabinet Office and the army on top secret plans - only recently declassified - which were entitled The Machinery of Government in War. They led to the establishment of a 34-acre underground bunker at Corsham in Wiltshire, to which the nation’s elite would have retreated.

Blast proof and completely self-sufficient, the underground site - codenamed Burlington - could accommodate up to 4,000 people, in complete isolation from the outside world, for up to three months.

I used to live 3 miles from there! XD