group of islands in the Arafura Sea off the northern coast of Arnhem Land in Northern Territory, northern Australia. They comprise South Goulburn Island (30 square miles 【78 square km】), lying 2 miles (3 km) offshore across Macquarie Strait; North Goulburn Island (14 square miles 【36 square km】), 10 miles (16 km) offshore; and some small sandy islets. Perhaps sighted in 1644 by the Dutch navigator Abel Tasman, they were named in 1818 by Captain Phillip Parker King after Henry Goulburn, then British under secretary of state for the colonies. Now part of Arnhem Land Aboriginal Reserve, the islands are under control of the traditional Aboriginal (Australian Aborigine) owners.