Australia is a relatively flat area of the world, with its highest peak barely reaching the 2 km mark. It makes up for what mountains it doesn't have by having thousands of rocky outcroppings, beautiful landmarks and breathtaking natural rocky formations. Being a country with more kangaroos then humans, it's incredibly likely that hundreds or even thousands of different cryptids are hidden by the endless sandy dunes or dense rainforests.
Australia is separated into many different biomes ranging from tropical rainforests in the north east, temperate coastal shores (one of the few hospitable areas), shallow atolls and reefs, and - for the most part - vast expanses of scorching and inhospitable deserts; at least for humans. on the remote southern island of Tasmania, lush sub polar rainforests exist, hiding possibly hundreds of Cryptic creatures like the Thylacine and Yowie.