Olympic Tower glitterati of that time. The planned use of the building was a groundbreaking concept at that time because it was the first mixed use zoned for Fifth Avenue, which had 21 floors of offices, 30 of condominiums and high-end retail on the first floor. It was constructed by shipping magnate Aristotle Onassis and his company, Victory Development, in joint venture partnership with Arlen Realty & Development Corporation. Olympic Tower was designed by the architectural firm of Skidmore, Owings and Merrill, notable for designing Willis Tower, the former Sears Tower and John Hancock Center in Chicago, among many other high-rise buildings
Equitable Building (Chicago) Equitable Building (Chicago) 401 North Michigan is a 35-story skyscraper in the Streeterville area of Chicago, built in 1965 at 401 North Michigan Avenue, along the north bank of the Chicago River. Along with the Tribune Tower and Wrigley Building, it forms the southern gateway to Chicago's famous Magnificent Mile. The building was built atop the site of a cabin belonging to Chicago's first permanent resident, Jean Baptiste Pointe du Sable. In reference to du Sable, the large plaza adjacent to the building has been named Pioneer Court. 401 North Michigan occupies a site with several aspects of historical significance,