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
New York–New Jersey Highlands River in Connecticut, encompassing the Reading Prong. In New Jersey, the region's watershed is protected by the state's own Highlands Water Protection and Planning Act. In addition to preserving water resources, the act supports open space preservation and the creation of new recreational parks and hiking trails in America's most densely populated state. New York–New Jersey Highlands The New York – New Jersey Highlands is a geological formation composed primarily of Precambrian igneous and metamorphic rock running from the Delaware River near Musconetcong Mountain, northeast through the Skylands Region of New Jersey along the Bearfort Ridge and the Ramapo Mountains,