<P> The Bronx ( / brɒŋks / ) is the northernmost of the five boroughs of New York City , in the U.S. state of New York . It is south of Westchester County ; north and east of Manhattan , across the Harlem River ; and north of Queens , across the East River . Since 1914 , the borough has had the same boundaries as Bronx County , the third-most densely populated county in the United States . </P>
which river separates the bronx in new york city from manhattan island
Harlem River