U.S. Steel Tower, also known as the Steel Building (formerly USX Tower) is a 64-story, 256.34 m (841.0 ft) skyscraper with 2,300,000 sq ft (210,000 m2) of leasable space at 600 Grant Street in downtown Pittsburgh, Pennsylvania. It is the tallest skyscraper in Pittsburgh, the fourth tallest building in Pennsylvania, the 41st tallest in the United States, and the two hundred and twentieth tallest building in the world.