Newcastle is a large metropolitan area and the second-most-populous such area in New South Wales, Australia. Located at the mouth of the Hunter River, it serves as the hub of the Lower Hunter region, which includes parts of Newcastle, Lake Macquarie, Maitland, Cessnock, and Port Stephens Council. The city is the predominant urban center within the broader Hunter Region, situated in the central-eastern part of the Sydney Basin geologically.