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.
U.S. Steel Tower
In the planning stages, U.S. Steel executives considered making the building the world's tallest, but settled on and the distinction of being the tallest building outside New York and Chicago. However, it eventually lost even that distinction to newer buildings erected across the United States. Prior to 1970, the tallest building in Pittsburgh, at 44 stories, was the Gulf Building, now known as Gulf Tower.