Opened in 1990 near Monument Circle in Indianapolis, Salesforce Tower (formerly known as Bank One Tower, then Chase Tower, and originally conceived as American Fletcher Tower) is the tallest building in the U.S. state of Indiana. It surpassed the AUL Tower (now OneAmerica Tower) in Indianapolis for the distinction. The building's twin spires pierce into the Indianapolis skyline, while the 48 floors of office and retail space and 2 building equipment floors above that peak at the roof. It is the regional headquarters of Salesforce, which moved into the tower in the late-2010s and currently occupies a large amount of space in the building. While the tower has two spires of equal height, only one of them is functional as a transmission antenna. The other mast is merely an architectural decoration. The building was designed by KlingStubbins, and built by Indianapolis-based Huber Hunt & Nichols.