List of tallest buildings and structures
The tallest artificial structure is Burj Khalifa, a skyscraper in Dubai that reached in height on January 17, 2009. By April 7, 2008 it had been built higher than the KVLY-TV mast in North Dakota, USA. That September it officially surpassed Poland's Warsaw radio mast, which stood from 1974 to 1991, to become the tallest structure ever built. Guyed lattice towers such as these masts had held the world height record since 1954.
Willis Tower
The Willis Tower remains the second tallest building in the Americas (after One World Trade Center) and the Western Hemisphere. With a pinnacle height of , it is the third-tallest freestanding structure in the Americas, shorter than Toronto's CN Tower. It is the eighth-tallest freestanding structure in the world by pinnacle height.