The CN Tower, located in Downtown Toronto, Ontario, Canada, is a communications and observation tower standing 553.3 metres tall. It surpassed the height of the Ostankino Tower 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 is 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 second-place ranking.
The CN Tower opened to the public on June 26, 1976, although the official opening date was October 1. The construction costs of approximately CDN$63 million ($330 million in 2005) were repaid in fifteen years. Canadian National Railway sold the tower prior to taking the company private in 1995, when they decided to divest themselves of all operations not directly related to their core freight shipping businesses.