U.S. Steel Tower, also known as the Steel Building (formerly USX Tower) is a 64-story, skyscraper with 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. It held its opening dedication on September 30, 1971.