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 mountain ranges like the Great Dividing Range. The interior of Australia, often referred to as the Outback, is characterized by arid conditions and sparse vegetation. Coastal regions are more populated and feature major cities such as Sydney, Melbourne, and Brisbane. Australia is also home to unique ecosystems, including the Great Barrier Reef, the world's largest coral reef system.