Australia is the sixth-largest country in the world, located in the Southern Hemisphere. It is surrounded by the Indian Ocean to the west and the Pacific Ocean to the east. The country is known for its diverse landscapes, which include vast deserts, tropical rainforests, and beautiful coastlines. The Great Barrier Reef, the world's largest coral reef system, is located off the northeastern coast. The interior of Australia, known as the Outback, is characterized by arid conditions and sparse vegetation. Major cities like Sydney, Melbourne, and Brisbane are situated along the eastern coast, where the climate is more temperate. Australia also has unique geographical features, such as the Australian Alps and the Nullarbor Plain.