Located on the western side of Admiralty Gulf and a part of the Bonaparte Archipelago, the island encompasses an area of 2,361 hectares (5,834 acres).

[2] The traditional owners of the area are the Uunguu peoples of the Wunambal language group, whose name for the island is Ngurraali.

[3] The group was named in 1891 by Phillip Parker King after John Osborn, one of the Lords of the Admiralty.

[1] The air-breathing land snails, Kimberleymelon tealei and Carinotrachia admirale are both endemic to the island.

The then immigration minister, Chris Bowen was attacked by the opposition over his "porous border protection policies".