List of tallest buildings and structures
The world's tallest artificial structure is the Burj Khalifa in Dubai (of the United Arab Emirates). The building gained the official title of "Tallest Building in the World" and the tallest self-supported structure at its opening on January 9, 2010. The second-tallest self-supporting structure and the tallest tower is the Tokyo Skytree. The tallest guyed structure is the KVLY-TV mast.
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.