Toronto Pearson International Airport — Toronto, Canada

Toronto Pearson International Airport, whose code is YYZ, spreads across the suburb of Mississauga just west of downtown Toronto and stands as Canada's busiest airport by a wide margin. It opened in 1939 as Malton Airport and was renamed decades later for Lester B. Pearson, the Canadian prime minister and Nobel Peace Prize laureate. Air Canada operates its largest hub here, funneling connections between the United States, Europe, Asia, the Caribbean, and Latin America through two passenger terminals after an older building was retired. Five runways handle a relentless stream of arrivals and departures, supporting tens of millions of travelers every year alongside heavy air cargo volumes. A dedicated rail link speeds passengers downtown in about 25 minutes. For much of the country, YYZ effectively functions as the front door to international travel.