Roughly triangular in shape, it is bounded on the north by Staten Island and Long Island and on the south by mainland New Jersey. Besides the Hudson River (which empties through the Narrows), the bay is fed by the Arthur Kill and the Raritan River, as well as by several smaller streams.
The section of the bay near the confluence of the Arthur Kill and the Raritan River is called Raritan Bay. The bay opens out to the ocean between two spits of land, Sandy Hook in New Jersey and Rockaway Point on Long Island.
Historically, the Lower Bay has been the primary means of marine access to New York Harbor, and more recently to Port Newark-Elizabeth Marine Terminal.
Since the time of the American Indians, the Lower Bay has provided a rich fishing ground but was restricted due to pollution in the Twentieth Century. In the Nineteeth Century, the shallow shoals on the south shore of Staten Island were a rich oyster bed.
The bay contains several popular beaches at Brighton Beach on Coney Island in Brooklyn, as well as Gateway National Recreational Area on Staten Island.