The Diefenbunker is Canada’s most significant surviving Cold War artifact — it is an impressive four-storey underground facility that operated as the country’s central communications headquarters during the Cold War, ready at any moment in case of a nuclear attack. Today, it is a one-of-a-kind museum and national historic site, telling stories of national and international importance. Descend into history, 75 feet underground, and explore Ottawa’s immersive history destination.