John Hancock Center
Although many confuse the Hancock Center and the Sears Tower (both are black super-towers in Chicago), the Hancock Center is unique in that it is a single tapered tower while the Sears Tower consists of several individual towers that give the structure its collective strength. With a single steel exoskeleton with a tapered shape, the 100-story tower is visibly unique from all other buildings in Chicago.
The Hancock Tower
The Sears Tower (now Willis Tower) looks quite different from the Hancock Tower.