The Bronx is the northernmost of the five boroughs of New York City. Coextensive with Bronx County, it was the last of the 62 counties of New York State to be incorporated. Located north of Manhattan and Queens, and south of Westchester County, the Bronx is the only borough that is located primarily on the mainland (a very small portion of Manhattan, the Marble Hill neighborhood, is physically located on the mainland, due to the rerouting of the Harlem River in 1897).