Citigroup Center is a 42 story, 588-foot (180 m) skyscraper in Chicago, Illinois. Located at 500 W. Madison (between Clinton and Canal Streets), the structure was designed by the architecture firm Murphy/Jahn in a late modernist style. The building, previously named the Northwestern Atrium Center, was constructed between 1984 and 1987 on the air rights obtained by the destruction of the headhouse of the 1911 North Western Station.