Hudson River Park is a waterside park on the North River (Hudson River), and is the part of the Manhattan Waterfront Greenway that extends from 59th Street south to Battery Park in the New York City borough of Manhattan. It is a joint state and city collaboration. It is a 550-acre (2.2 km²) park stretching 4.5 miles (7.2 km), making it the second-biggest park in Manhattan after Central Park.