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. Though Burj Khalifa is the tallest free-standing structure, the CN Tower remains the world's tallest tower, according the Guinness Book of World Records 2010, although the Guangzhou TV & Sightseeing Tower surpassed the height of the CN Tower in 2009.
CN originally referred to Canadian National, the railway company that built the tower. Following the railway's decisi