Geography of New York City the coast of the Northeastern United States at the mouth of the Hudson River in southeastern New York state. It is located in the New York–New Jersey Harbor Estuary, the centerpiece of which is the New York Harbor, whose deep waters and sheltered bays helped the city grow in significance as a trading city. Much of New York is built on the three islands of Manhattan, Staten Island, and western Long Island, making land scarce and encouraging a high population density. The Hudson River flows from the Hudson Valley into New York Bay, becoming a tidal estuary that separates the
Geography of New Jersey Island by the Kill van Kull and the Arthur Kill. Liberty Island is an exclave of State of New York in New Jersey waters in Upper New York Bay. Ellis Island, also in the Upper Bay, and Shooter's Island, in Newark Bay, each have sections belonging to either of the two states. On its west, New Jersey is flanked by the Delaware River that forms its border with the Commonwealth of Pennsylvania and Delaware Bay which separates New Jersey from the State of Delaware. However, due to a fluke in a colonial land grant for the city of New Castle,