We would like to invite you for a social night at Diefenbunker. The Diefenbunker: Canada’s Cold War Museum has been named Canada’s most significant Cold War site for visitors interested in culture and history. This National Historic Site of Canada is an underground nuclear bunker built in secrecy during the height of the Cold War, located just 35 km from Ottawa. As the Central Emergency Headquarters, it was meant to house the top officials of the government and military during the risk of nuclear attack.