There are many salt lakes or playas in the arid zone of Australia, in fact they are almost as numerous as freshwater lakes. One only has to fly across the continent to see the endless longitudinal sand dunes interspersed with shining white salt lakes. Some, like the hundreds of lakes that make up the Peera Peera Poolawanna lake system in the south eastern Simpson Desert are palaeodrainage basins, remnants of earlier fresh water lakes, others are terminal lakes, like Lake Eyre. The Serpentine Lakes in the Great Victoria Desert are the remnants of palaeodrainage channels. There are a number of lakes in the Tirari Desert, like Lake Palankarinna, which contains some of Australia's most important fosssil deposits. In the Tirari there is also the hauntingly beautiful Lake Florence. In the Great Sandy Desert there is the massive Lake Disappointment.

The lakes are often difficult to cross with vehicles and can become quite boggy, especially after rain. Driving on the lakes is not only risky, but you leave unsightly tyre tracks to spoil future visitor's vistas for a long time to come. Salt Lakes confounded early explorers, like Edward John Eyre, proponent of the horseshoe theory. He surmised by repeated attempts to head north being thwarted by salt lakes, that Adelaide was surrounded by a horseshoe of salt lakes to the north making penetration into the inland impossible. In fact he just kept running into different lakes.

The salt playas themselves support very little vegetation. A number of organisms living in salt lakes are of commercial interest, for example brine shrimp which makes an excellent animal foodstuff, and organisms that produce glycerol and b-carotene which often give lakes a pink hue. Chenopods and the salt tolerant Eragrostis grasses tend to dominate the fringes of the lakes. There is a commonality of vegetation as one travels across Australian deserts. Coming to salt lakes in the far north after being in deserts to the south east, one encounters the same plants, almost like seeing old friends. Some of the larger lakes, invariably connected with river systems, support a wide variety of aquatic fauna, and this is discussed in our section on Lake Eyre.