Australia is one of the flattest and oldest landmasses on Earth, with an average elevation of only about 330 meters. Most of the continent is low-lying plains and plateaus, but the landscape varies dramatically from region to region: red desert in the interior, a long mountain spine along the eastern coast, tropical rainforest in the north, and fertile farmland in between. Roughly 18% of the mainland is classified as desert, and agriculture covers about 57% of the total land area.
The Western Plateau
The western two-thirds of Australia sits on an ancient plateau that has existed as a landmass for more than 500 million years. This makes it some of the oldest exposed rock on the planet. The plateau is made up of several individual plateaus, including the Kimberley in the far north, the Hamersley in the northwest, and the Yilgarn in the southwest. The terrain here is generally flat to gently undulating, with red and ochre soils, sparse vegetation, and rocky outcrops that have been worn down by hundreds of millions of years of erosion.
Because Australia sits in the middle of a tectonic plate rather than at the edge of one, it has no active volcanoes and very little mountain-building activity. Earthquakes do occur across the continent, but they’re intraplate events, typically mild compared to what happens along plate boundaries like those surrounding the Pacific. This tectonic calm is a big reason the landscape has been ground down so flat over time.
The Interior: Desert and Dry Plains
The center of Australia is famously flat, but it’s not featureless. Mountain ranges like the MacDonnell and Musgrave Ranges break up the interior, and isolated rock formations dot the landscape. The most famous of these is Uluru, a sandstone monolith that rises abruptly from the surrounding plains in the Northern Territory. The interior is overwhelmingly arid, with summer temperatures regularly exceeding 35°C and rainfall that arrives unpredictably, sometimes not at all for months.
Australia’s named deserts, including the Simpson, Great Victoria, Gibson, and Tanami, together cover about 18% of the mainland. These aren’t all sand dunes. Some are stony plains, some are covered in hardy scrubland called spinifex, and some are salt flats. The Nullarbor Plain in the south is something different altogether: an uplifted ancient sea floor made of limestone, stretching flat and almost treeless for hundreds of kilometers along the coast of the Great Australian Bight.
The Great Dividing Range
Running roughly parallel to the east coast, the Great Dividing Range stretches nearly 4,000 kilometers from the tip of Cape York Peninsula in far north Queensland south to the Grampians in Victoria. It’s the most prominent mountain chain on the continent, though by global standards it’s modest in height. Average elevations through Queensland sit between 600 and 900 meters, with some peaks in the Bellenden Ker and McPherson ranges reaching 1,500 meters.
The highest point on the continent is Mount Kosciuszko, at 2,228 meters, located in the Australian Alps near the New South Wales and Victoria border. The Alps are the only part of the mainland that receives regular snowfall, and they look nothing like the arid interior most people picture when they think of Australia.
The Great Dividing Range plays a critical role in shaping the continent’s climate and water systems. It acts as a continental divide: rivers on the steep eastern slope, like the Snowy River, flow quickly down to the Pacific Ocean. Rivers on the gentler western slope, including the Darling, Lachlan, Murrumbidgee, and Goulburn, drain slowly inland to eventually join the Murray River. This western side of the range creates a rain shadow effect, which is one reason the interior is so dry.
Coastal and Tropical Landscapes
Australia’s coastline stretches for nearly 60,000 kilometers when you include islands, and the landscapes along it vary enormously. The east coast, sheltered by the Great Dividing Range, receives the most rainfall and supports dense eucalyptus forests, temperate rainforest in the south, and tropical rainforest in far north Queensland. The northeast coast is also home to the Great Barrier Reef, the world’s largest coral reef system, which sits just offshore in warm, shallow waters.
The tropical north, including parts of Queensland, the Northern Territory, and Western Australia, experiences a wet-dry monsoon climate. During the wet season, rivers flood across vast floodplains. During the dry season, the same land can crack and harden under relentless sun. The far southwest corner around Perth has a Mediterranean climate with mild, wet winters and hot, dry summers, supporting forests of towering karri and jarrah trees that exist nowhere else.
How the Land Is Used
Agriculture dominates Australia’s land use, covering about 439 million hectares, or 57% of the total land area. But that number is misleading if you picture green cropland. The vast majority of agricultural land is used for grazing livestock on enormous pastoral stations, some of which are larger than small European countries. The soil over much of the interior is too thin and nutrient-poor for cropping. Productive farmland for crops like wheat, barley, and sugarcane is concentrated in a relatively narrow band along the east, southeast, and southwest coasts where rainfall is more reliable.
The remaining land is split between nature reserves, forests, and land that’s simply too remote or harsh for any economic use. Large portions of the interior are essentially uninhabited, with population density in some regions dropping below one person per 100 square kilometers. Most Australians live within a few dozen kilometers of the coast, clustered in cities along the eastern and southeastern seaboard. The contrast between the densely settled coastline and the vast, empty interior is one of the defining features of Australia’s geography.