seaboard lagoon, New South Wales, Australia. It lies 60 miles (97 km) northeast of Sydney. Measuring 15 miles long and 5 miles wide (24 km long and 8 km wide), with 108 miles (174 km) of shoreline and an area of 45 square miles (117 square km), it was formed by sandbars closing off three small branching estuaries of the Hunter River (leaving one narrow passage open to the Pacific that is the site of the small resort and industrial town of Swansea). The lake, named after former governor Lachlan Macquarie (Macquarie, Lachlan), is the focus of recreational, commercial, and residential development. Coal is mined on the eastern and western shores. Superphosphates and sulfuric acid are produced at a plant on Cockle Creek, which enters the lake from the north. The lake's waters are used by the power station at Vales Point. A wildlife sanctuary is located on Pulbah Island.