The York Cold War Bunker is a two-storey, semi-subterranean, Cold War bunker in the Holgate area of York, England, built in 1961 to monitor nuclear explosions and fallout in Yorkshire, in the event of nuclear war. One of about 30 around the United Kingdom, the building was used throughout its operational existence as the regional headquarters and control centre for the Royal Observer Corps's No. 20 Group YORK between 1961 and 1991.