The great of the tallest structures on Earth, as of April 2007, is the KVLY-TV mast, a 628.8m (2,063 ft) tower located in Blanchard, South Dakota, near the town of Fargo. It is a thin metal frame supported by guy wires. The Warsaw radio mast in Gąbin-Konstantynów, Poland, near Warsaw, used to be the tallest structure on earth at 646.4 m (2,120 ft), but it collapsed catastrophically on 8 August 1991. There are dozens of other radio masts and television towers over 2,000ft (610 m) in height.
There is some controversy as to whether or not these towers truly qualify as the tallest structures. The reason why is that these tallest structures are not self-supporting, but require wires to stay up. If we were to truly include all non-self-supporting structures, moored balloons would be the winner by far, with some of the longest extending up to 25,000ft (~5 miles) into the atmosphere. Moored balloons are high-altitude balloons kept in place by a tether that extends to the ground. As an example, the United States Drug Enforcement Administration (DEA) has contracted with Lockheed Martin to launch about a dozen moored balloons, or aerostats, to create the Tethered Aerostat Radar System, a series of balloon radars designed to detect low-flying craft breaching the southern border of the United States.
The tallest structure of any type, ever, is currently being built in Dubai, in the United Arab Emirates. The tower is called Burj Dubai, which means "Tower of Dubai" in Arabic. Burj Dubai's final height is being kept a secret, but its developers have stated the tower will be at least 705 meters (2,313 feet) tall. More recently, a contracting company building the tower stated it will be "over 940 meters", or at least 3,084 feet tall. Whatever its final height, it is almost certain to break all prior height records, reigning as the world's new tallest structure, if completed. It will have between 160 and 216 floors.
The interior of Burj Dubai will be designed by Giorgio Armani. The lower 37 floors will be occupied by the Armani Hotel, the first of its kind. Floors 45 through 108 will have 700 apartments, which sold out within eight hours at millions a pop. Corporate offices and suites will fill the remaining floors. The tower's unique lotus, multi-staged design will give several floors large outdoor spaces, which will be used for pools, bars, etc. An observation deck will be on the 124th floor. The Burj Dubai will truly be a king among the world's tallest structures.
Michael is a longtime WiseGEEK contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.