The island of Manhattan is surrounded by three rivers, the Hudson River, once called North River West (to the west), the East River (to the east) and the Harlem River to the north-east.

Manhattan is an island famously flanked by two major bodies of water: the Hudson River to the west and the East River to the east. Interestingly, from a geological standpoint, only the Hudson is a true river. The Hudson River (also historically known as the North River) originates in the Adirondack Mountains and flows south into the Atlantic Ocean. The East River is actually a saltwater tidal strait that connects Upper New York Bay to the Long Island Sound; it doesn't have a traditional river source. There is also a third, smaller body of water called the Harlem River, which is another tidal strait separating Manhattan from the Bronx to the north. These waterways define the island's famous skyline and are crossed by dozens of iconic bridges and tunnels. The Hudson is significantly wider (about one mile) compared to the East River, and both play a critical role in the city's climate, transportation, and recreation, though the East River's currents are notoriously swift due to its tidal nature.