CN Tower
"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 listed 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 shorter than the CN Tower. The issue of what was tallest became moot when Burj Khalifa, then under construction, exceeded the height of the CN Tower in 2007 (see below).
Taipei
Taipei 101 is a 101-floor landmark skyscraper that claimed the title of world's tallest building when it opened in 2004, a title it held for six years before relinquishing it to the Burj Khalifa in Dubai. Designed by C.Y. Lee & Partners and constructed by KTRT Joint Venture, Taipei 101 measures from ground to top, making it the first skyscraper in the world to break the half-kilometer mark in height. Built to withstand typhoon winds and earthquake tremors, its design incorporates many engineering innovations and has won numerous international awards. Taipei 101 remains one of the tallest skyscrapers in the world and holds LEED's certification as the world's largest "green" building. Its shopping mall and its indoor and outdoor observatories draw visitors from all over the world. Taipei 101's New Year's Eve fireworks display is a regular feature of international broadcasts.