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 becoming the tallest free-standing structure on land in the world for the next 31 years.
 

 

Guinness World Records has called the CN Tower "the world's tallest self-supporting tower" and "the world's tallest free-standing tower". Although Guinness did list this description of the CN Tower under the heading "tallest building" at least once, it has also listed it under "tallest tower", omitting it from its list of "tallest buildings." In 1996, Guinness changed the tower's classification to "World's Tallest Building and Freestanding Structure". Emporis and the Council on Tall Buildings and Urban Habitat both list the CN Tower as the world's tallest free-standing structure on land, and specifically state that the CN Tower is not a true building, thereby awarding the title of world's tallest building to Taipei 101, which is 44 metres (144 ft) shorter than the CN Tower. The tower's official web site, however, still claims it is the "world's tallest building" as of 2008.