Chicago Many other architects have left their impression on the Chicago skyline such as Daniel Burnham, Louis Sullivan, Charles B. Atwood, John Root, and Helmut Jahn. The Merchandise Mart, once first on the list of largest buildings in the world, currently listed as 44th-largest (), had its own zip code until 2008, and stands near the junction of the North and South branches of the Chicago River. Presently, the four tallest buildings in the city are Willis Tower (formerly the Sears Tower, also a building with its own zip code), Trump International Hotel and Tower, the Aon Center (previously the Standard
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,