The Diefenbunker is a four-storey underground bunker built in the late 1950s under Prime Minister John Diefenbaker to shelter the Canadian government from nuclear attack. Located at Carp, about 35 kilometres west of Ottawa, it was designed to house 535 people for a month following a nuclear strike and contains a complete parallel government infrastructure: Cabinet War Room, Bank of Canada vault, CBC broadcast studio, and a decontamination chamber at the entrance.
It operated as a secret military facility until 1994 and is now a cold war museum — one of the most unusual in Canada. Self-guided tours take ninety minutes to two hours and cover the full four levels, giving an extraordinary picture of 1960s nuclear anxiety and Canadian Cold War planning. The sets are intact: the Cabinet Room still has the original maps on the wall, the hospital is fully equipped, and the Prime Minister's suite is furnished as it was. The Diefenbunker also appears in several films and TV productions and has become something of a cult attraction. Driving from Ottawa takes about 45 minutes; a shuttle sometimes runs from the city in summer.