The islands are more than 4000 kilometres southwest of Australia in the Indian Ocean sector of the Southern Ocean. They are 1500 kilometres north of Antartica at around 53° 05' S and 73° 30' E.
They were unknown to men until the 19th century.
Heard Island, with an area of 368 square kilometres, is the principal island of the territory.
McDonald Island, with an area of 1 square kilometre, lies 43.5 kilometres west of Heard of Island. It is the major island in the McDonald Islands group, which also includes Flat Island and Meyer Rock.
Heard Island and the McDonald Islands are volcanic in origin. They are a habitat for sub-Antarctic plants and animals.
Heard Island and McDonald Islands Marine Reserve was declared on October 16, 2002, to protect the conservation values of the reserve area, the territorial sea and the adjacent exclusive economic zone.
The Territory of Heard Island and McDonald Islands is administered from Canberra by the Australian Antarctic Division of the Department of the Environment and Heritage.
Heard Island and McDonald Islands were inscribed as a World Heritage site in 1997.
