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
Tribune Tower Tribune Tower The Tribune Tower is a neo-Gothic skyscraper located at 435 North Michigan Avenue in Chicago, Illinois, United States. It was the home of the "Chicago Tribune", Tribune Media, and tronc, Inc., formerly known as Tribune Publishing. WGN Radio (720 kHz) originated broadcasts from the building until moving to 303 Wacker Drive in June, 2018. The last WGN Radio broadcast emanated from the Tribune Tower on June 18, 2018. The ground level houses the large restaurant Howells & Hood (named for the building's architects), whose patio overlooks nearby Pioneer Court and Michigan Avenue. CNN's Chicago bureau was also located