The Bronx is the northern part of New York City, United States. The name came from Bronck's Farms, owned by a settler called Jonas Bronck. The Bronx was once the southern part of Westchester County, but is now one of the five boroughs of New York City as well as a county in New York State called Bronx County. The Bronx River flows south out of Yonkers and Mount Vernon, New York, through the middle of The Bronx, and into Long Island Sound.