Venture four storeys underground and enter the classified world that was the Cold War era. Built in secrecy by the Canadian government, the underground bunker was made to house top government and military officials in the event of an attack. The nuclear bunker, a National Historic Site of Canada, is now Canada’s Cold War Museum. It provides a unique peek into this era dominated by secrets, fear, and anxiety. See where the prime minister — John Diefenbaker at the time, who commissioned the bunker — would have slept, imagine the emergency broadcasts that would have emanated from the radio studio that is built into the bunker, and walk inside the Bank of Canada vault.