The CN Tower, sometimes formally referred to as Canada's National Tower, is a communications and observation tower in Downtown Toronto, Ontario, Canada. Standing 553.3 metres (1,815 ft) tall, it was completed in 1976, becoming the world's tallest free-standing structure and world's tallest tower. It held both records for 34 years until the completion of Burj Khalifa in Dubai and Canton Tower in Guangzhou. It remains the tallest free-standing structure in the Western Hemisphere, a signature icon of Toronto's skyline, and a symbol of Canada, attracting more than two million international visitors annually.
Its name "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 second-place ranking.