The CN Tower, located in Downtown Toronto, Ontario, Canada, is a communications and observation tower standing 553.3 metres (1,815 ft) tall.[2] It surpassed the height of the Ostankino Tower becoming the tallest free-standing structure on land in the world for the next 31 years. 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 consists of several substructures. The main portion of the tower is a hollow concrete hexagonal pillar containing the six elevators, stairwells, and power and plumbing connections. On top of this is a 102-metre (334.6 ft) tall metal broadcast antenna, carrying TV and radio signals. There are two visitor areas: the main deck level (formerly known as SkyPod) located at 346 metres (1,135 ft), and the higher Sky Pod (formerly known as "Space Deck") at 446.5 metres (1,465 ft),[10] just below the metal antenna. The hexagonal shape can be seen between the two areas; however, below the main deck, three large supporting legs give the tower the appearance of a large tripod.