Wilpena Pound

From the air, Wilpena Pound looks like a crater, a massive bowl almost 100 kilometres (62 miles) wide that stands above the surrounding plains. But the rim is actually made up of the stumps of huge mountains, believed to have been as high as the Himalayas, that have been eroded over millennia. There's only one way in: through a gorge 11 kilometres (seven miles) long and eight kilometres (five miles) across. It was called a pound by the early settlers in the 1850s – they thought it looked like a traditional sheep pen. The best way to see the distinctive shape is on a scenic flight from inside the Pound.