Triborough, TRY bur oh, Bridge connects three boroughs of New York City--Manhattan, the Bronx, and Queens. This great structure is actually a series of bridges forming three steel and concrete arms that form a rough Y in shape. The total length of the three arms is 171/2 miles (28.2 kilometers), of which about 31/2 miles (5.6 kilometers) consist of bridges and viaducts. The four overwater spans cross the East and Harlem rivers, the Bronx Kills, and Little Hell Gate.