The CN Tower, located in downtown Toronto, Ontario, Canada, is a communications and observation tower standing 553.3 metres (1,815 ft) tall. It surpassed the height of the Ostankino Tower while still under construction in 1975, becoming the tallest free-standing structure on land in the world for the next 31 years. On September 12, 2007 the CN Tower was surpassed in height by Burj Khalifa (formerly known as Burj Dubai). It remains the tallest free-standing structure in the Western Hemisphere, the signature icon of Toronto’s skyline, and a symbol of Canada, attracting more than two million international visitors annually.
CN originally referred to Canadian National, the railway company that built the tower. Following the railway’s decision to divest non-core freight railway assets, prior to the company’s privatization in 1995 it transferred the tower to the Canada Lands Company, a federal Crown corporation responsible for real estate development. Since local residents wished to retain the name CN Tower, the abbreviation is now said to expand to Canada’s National Tower rather than the original Canadian National Tower; however, neither of these names are commonly used.
In 1995, the CN Tower was declared one of the modern Seven Wonders of the World by the American Society of Civil Engineers. It also belongs to the World Federation of Great Towers, where it holds the 1st place ranking.