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).
List of tallest buildings and structures
One historic case involved the building now famous for the Times Square Ball. Known as One Times Square (at 1475 Broadway in Midtown Manhattan), it was the headquarters for " The New York Times, " which gave Times Square its name. Completed in 1905, it reached a height of to its roof, or including its rooftop flagpole, which the " Times " vainly hoped would give it a record high status. But because a flagpole is not an integral architectural part of a building, One Times Square was not generally considered to be taller than the Park Row Building in Lower Manhattan, which was therefore still New York's tallest.