What Lies Beneath: At first glance Montreal does not appear to be overcrowded, but maybe that’s because everyone is underground. More than four and a half square miles make up this second city—the world’s largest underground complex, with 4,350 hotel rooms, 2,727 apartments, 930 retailers, 68 metro stops, nine fitness centers, three skating rinks, two libraries, and a chapel.
How Did It Get There: Montreal’s known for its brutal winters, so in 1962, while breaking ground for the city’s first metro, the idea for an underground shopping mall was born.
Cool Bonus: “If you live in one of the underground apartments you can take the metro to work, come back, do your shopping,” says Bertin Jacques, manager of Tourism Montreal. “You can spend a week down there without sticking your nose out.”