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
Elgin Tower Building 1999 to showcase its architectural merit. Stickling died later that year, but his benefactors transferred the building to the William R. Stickling Charitable Foundation, who currently maintain the building. An addition was built in 1999 to house, rent-free, the Downtown Neighborhood Association, who intend to revitalize the downtown area. The tower was added to the National Register of Historic Places on May 22, 2002. The Elgin Tower Building is located at 100 E. Chicago St. in Elgin, between Douglas and N. Grove Avenues. This area has historically been known as Fountain Square, generally accepted as the downtown area of Elgin.