[4][5] The bunker is important as an engineering achievement and to the critical path method of planning used in its construction.

Fortunately, it never served its intended purpose, although the Diefenbaker government made plans to retreat to its protection during the Cuban missile crisis of 1962.

The bunker functioned as the hub of a communications network[8] and civil defence system until it closed in 1994.

[1] In 1958, at the height of the Cold War and the infancy of the intercontinental ballistic missile (ICBM) threat, Prime Minister John Diefenbaker authorized the creation of close to 50 Emergency Government Headquarters (nicknamed "Diefenbunkers" by opposition parties[9]) across Canada.

It had massive blast doors at the surface, as well as extensive air filters to prevent radiation infiltration.

[9] Although supposedly effective against surface nuclear detonations, the facility was later found to be vulnerable to conventional Bunker buster bombs developed after its construction, as these bombs had time delay fuses that would detonate after they had penetrated deeply enough underground.

These facilities were administered by the Royal Canadian Corps of Signals (later the Communications and Electronics Branch).

[11] The local municipality took control of the facility and a group of local volunteers, recognizing the heritage and tourism value of the Carp Diefenbunker, undertook to open the facility as a cold war museum and conduct public tours.

[10][9] Many areas of the bunker, including the PM's Suite, the Emergency Government Situation Centre, the CBC Emergency Broadcasting Studio, the Military Federal Warning Centre, the External Affairs Ministerial Office, the Public Works Minister's Office and the Bank of Canada Vault, are being restored to their operational condition.

[19] The Diefenbunker houses a collection of Cold War artifacts, an archive and a library, all of which are made available to researchers upon request, and to the general public through the exhibitions.

[9] The decommissioned bunker has been used as a movie set on several occasions, including for The Sum of All Fears[9] and Rulers of Darkness.