Aon Center (Chicago) the world headquarters of Aon and Amoco. Aon's US operations are still headquartered here. The building is also the co-headquarters of Kraft Heinz. The Standard Oil Building was constructed as the new headquarters of the Standard Oil Company of Indiana, which had previously been housed at South Michigan Avenue and East 9th Street. When it was completed in 1973, it was the tallest building in Chicago and the fourth-tallest in the world, earning it the nickname "Big Stan". (A year later, the Sears Tower took the title as Chicago's and world's tallest.) The building employs a tubular steel-framed structural system
The Buckingham (Chicago) floor of the building for a total of 306 units. An indoor pool, sauna, laundry room, fitness center and open roof deck are located on the top floor. The Buckingham has 3 high-speed elevators that run the length of the building plus one elevator that runs from the first floor to each floor of the 4-story underground parking garage. The Buckingham is east of 340 on the Park. It appears (unlabelled) in front of Park Tower (Chicago) in the diagram below. The Buckingham (Chicago) The Buckingham, formerly known as Buckingham Plaza, is a 44-story all-residential condominium designed by Fujikawa Johnson