The Territory of Heard Island and McDonald Islands (HIMI) is an Australian external territory comprising a volcanic group of barren Antarctic islands, about two-thirds of the way from Madagascar to Antarctica. The group's overall size is 372 square kilometres (144 sq mi) in area and it has 101.9 km (63 mi) of coastline. Discovered in the mid-19th century, the islands have been an Australian territory since 1947 and contain the country's only two active volcanoes. The summit of one, Mawson Peak, is higher than any mountain on the Australian mainland. The islands lie on the Kerguelen Plateau in the Indian Ocean.
The islands are among the most remote places on Earth: They are located approximately 4,099 km (2,547 mi) southwest of Perth, 3,845 km (2,389 mi) southwest of Cape Leeuwin, Australia, 4,200 km (2,600 mi) southeast of South Africa, 3,830 km (2,380 mi) southeast of Madagascar, 1,630 km (1,010 mi) north of Antarctica, and 450 km (280 mi) southeast of the Kerguelen Islands. The islands are currently uninhabited.