Australia is a country in the Southern Hemisphere (26)comprises the mainland of the Australian continent, the island of Tasmania, and many smaller islands in the Indian and Pacific Oceans. Neighbouring countries (27)Indonesia, East Timor, and Papua New Guinea (28)the north, the Solomon, Vanuatu, and New Caledonia to the northeast, and New Zealand to the Southeast. Australia (29)six states, and two major mainland territories.