Heard Island and McDonald Islands (abbreviated as HIMI ) are uninhabited, barren islands located in the Southern Ocean, about two-thirds of the way from Madagascar to Antarctica. They have been territories of Australia since 1947, and contain the only two active volcanoes in Australian territory, one of which, Mawson Peak, is the highest Australian mountain. The group's size is 372 km² in area.

History
Heard Island is a 368 km² bleak and mountainous island located at 53°06′00″S, 73°31′00″E. Its mountains are covered in glaciers and dominated by Mawson Peak, a 2,745 m (9,006 ft) high complex volcano which forms part of the Big Ben massif.
Mawson Peak is the highest Australian mountain (517 m higher than Mount Kosciuszko), and one of only 2 active volcanoes in Australian territory, the other being McDonald Island. A long thin spit named "Elephant Spit" extends from the east of the island.
There is a small group of islets and rocks about 10 km north of Heard Island, consisting of Shag Islet, Sail Rock, Morgan Island and Black Rock. They total approximately 1.1 km² in area.
The McDonald Islands are located 44 km to the west of Heard Island at 53°02′20″S, 72°36′04″E. The islands are small and rocky and consist of McDonald Island (230 m high), Flat Island (55 m high) and Meyer Rock (170 m high). They total approximately 2.5 km² in area and, as with Heard Island, are surface exposures of the Kerguelen Plateau.
McDonald Island after being dormant for 75,000 years, erupted in 1992 and has erupted again several times since, its most recent eruption being on the 10th August 2005.
Heard Island and the McDonald Islands have no ports or harbours.