At Union Square, Broadway crosses 14th Street, merges with Fourth Avenue, and continues its diagonal uptown course from the Square's northwest corner; Union Square is the only location wherein the physical section of Broadway is discontinuous in Manhattan (other portions of Broadway in Manhattan are pedestrian-only plazas). At Madison Square, the location of the Flatiron Building, Broadway crosses Fifth Avenue at 23rd Street, and is discontinuous to vehicles for a one-block stretch between 24th and 25th Streets. At Greeley Square (West 33rd Street), Broadway crosses Sixth Avenue (Avenue of the Americas), and is discontinuous to vehicles. Macy's Herald Square department store, one block north of the vehicular discontinuity, is located on the northwest corner of Broadway and West 34th Street and southwest corner of Broadway and West 35th Street; it is one of the largest department stores in the world.