The Heard Island and McDonald Islands (abbreviated as HIMI) are an Australian external territory and volcanic group of barren Antarctic islands, about two-thirds of the way from Madagascar to Antarctica. The group's overall size is in area and it has of coastline. Discovered in the mid-19th century, they have been territories of Australia since 1947 and contain the only two active volcanoes in Australian territory, the summit of one of which, Mawson Peak, is higher than any mountain on the Australian mainland. They lie on the Kerguelen Plateau in the Indian Ocean.
The islands are among the most remote places on Earth: They are located approximately southwest of Perth, southwest of Cape Leeuwin, Australia, southeast of South Africa, southeast of Madagascar, north of Antarctica, and southeast of the Kerguelen Islands. The islands are currently uninhabited.