Discover the Diefenbunker: Canada’s Cold War Museum! Now a museum and National Historic Site of Canada, this once-secret underground bunker in Carp, Ontario was built to protect the Canadian government from a nuclear attack in the Cold War. For 33 years, the entire building had to be prepared to sustain 535 people for 30 days at a moment’s notice. The Bunker’s machine room, an engineering marvel designed to make the facility completely self-sufficient in the event of an attack on Canada was the heart of the building. Go behind closed doors to discover this engineering marvel with the Diefenbunker’s new WalkThru tour.