A Brief History of the World's Tallest Buildings

CN Tower
Stretching more than 1,800 ft. (550 m) into the air is CN Tower — the tallest freestanding structure in the Americas and one of the modern Seven Wonders of the World. The tower — built by Canadian National Railway — was designed as a telecommunications hub to overcome the problem of poor reception caused by Toronto's skyscrapers. After its completion in 1976, the tower also became a downtown tourist attraction, and today more than 2 million visitors enjoy multiple observation decks, cafés and even a 360-degree revolving restaurant each year.

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