1. The Great Dividing Range: This is a mountain range that runs parallel to the east coast of Australia, stretching for over 3,500 kilometers. The range forms a natural barrier between the coastal plains and the inland.
2. The Murray-Darling River system: This is the largest river system in Australia, stretching for over 3,700 kilometers. The system includes some of the most iconic rivers in Australia, such as the Murray River, the Darling River, the Murrumbidgee River, and the Snowy River.