The Bronx is the northernmost of the five boroughs of New York City. The Bronx has a land area of 42 square miles (109 km2) and a population of 1,472,654 at the 2020 census. It has the fourth largest area, fourth largest population, and third highest population density of the boroughs. The Bronx is the only borough located primarily on the mainland, bordering Westchester County to its north; the Hudson River and the borough of Manhattan, across the Harlem River, to its west; the borough of Queens, across the East River, to its south; and Long Island Sound to its east. The borough is coextensive with Bronx County, one of the 62 counties of New York State.