The tallest building and tallest man-made structure in the world is the Burj Kalifa tower in Dubai. It’s 26-hundred-84 feet tall with 162 floors. It took the title on January 4, 2010. For a man-made structure to be considered a building, at least 50 percent of its height must be able to accommodate space for living space or offices.

That’s why the CN Tower in Toronto can never be considered a building. It had been the

CN Tower in Toronto from the Rogers Center (Getty Images)

world’s tallest structure until 2007 when construction of Burj Kalifa surpassed it.

Even since then the CN Tower has moved down to number two in the world in self-supporting towers. The Tokyo Sky Tree in Japan opened in 2011 and is 265-feet taller.

Then there’s yet another category – radio and TV towers. It’s a different category because they’re not self-supporting. They need guy wires or cables to keep them up. Without them they’d fall over. Currently the tallest broadcast tower in the world was built in 1963 – it’s the KVLY-TV broadcast tower in Blanchard, North Dakota. It tops out at 2,063 feet – taller than the CN Tower, but just a shade under the Sky Tree in Tokyo.