NOTES: Height is from top to bottom, antennas included. A tower differs from a building in that the latter has floors, and is designed for residential, business, or manufacturing use. The structures listed here are principally telecommunications towers, and while they may have observation decks or restaurants, they do not have floors all the way up. Towers and buildings are freestanding structures; this list does not include masts supported by guy wires. The tallest mast currently standing is the KVLY-TV Mast in North Dakota, built in 1963; it is 629 m (2,063 ft) tall. The tallest mast of all time was the Warszawa Radio Mast near Konstantynów, Poland, built in 1974; it was 646 m (2,120 ft) tall before collapsing during renovation work in 1991. (Note that the name of a building or mast may include the word “tower,” but that does not affect its status.) This list also does not include the Petronius Platform, built in 2000 in the Gulf of Mexico, which is 610 m (2,001 ft) tall without its spire, or 640 m (2,100 ft) with it. While it is the world's tallest freestanding structure, 535 m (1,754 ft) of it is underwater and it is partly supported by buoyancy.
