Fifth Avenue originates at Washington Square Park in Greenwich Village and runs northwards through the heart of Midtown, along the eastern side of Central Park, where it forms the boundary of the Upper East Side and through Harlem, where it terminates at the Harlem River at 142nd Street. Traffic crosses the river on the Madison Avenue Bridge. Fifth Avenue serves as the dividing line for house numbering in Manhattan. It separates, for example, East 59th Street from West 59th Street. From this zero point for street addresses, numbers increase in both directions as one moves away from Fifth Avenue, with 1 West 59th Street on the corner at Fifth Avenue, and 300 West 59th Street located three blocks to the west of it.