Lake Eyre, in the heart of South Australia’s outback, is the world’s largest ephemeral lake. Containing water or not, it's a phenomenal sight best admired from the air. You can catch a scenic flight from Wilpena Pound or William Creek (both in the breathtaking Flinders Ranges, five hours' drive north from Adelaide). Depending which flight you take, you may go over vast cattle stations, astonishing salt flats stretching to the horizon, and the outline of a 4.2 kilometre (2.1 mile) geoglyph (a large design visible from the air) known as the Marree Man. It's the world’s largest geoglyph, a mysterious and incredible desert artwork discovered almost two decades ago, that appears to depict an Aboriginal man hunting with a boomerang or stick. When you get to the lake you might see camels on the shoreline, along with thousands of birds, particularly when the lake is in flood.