"Mirabel International Airport ... will turn out to be one of Canada's greatest investments." -- Otto Lang, Transport Minister, 28 Feb 78
Montréal Mirabel Airport was opened in 1975 at the cost of $2 billion adjusted. Ultimately its tarmac and runway areas alone were to take up 70 km2 (27 mi2) of space and would have made it the world's largest airport. The airport never got any busier than Boise Airport is today, and the passenger terminals are now abandoned shells (slideshow). A key factor in the failure was that for 22 years authorities banned all international flights from the much-closer, thriving Dorval Airport, heavily used by locals and business travellers. It didn't help that Montreal was already sliding into decline in the 1970s due to the growth of the Great Lakes and Toronto-based economies and uncertainties about Quebec's political climate. Montreal is no stranger to alleged boondoggles: Olympic Stadium, half-finished during the 1976 Summer Games, spiralled $1 billion over budget.