Okavango Delta

The Okavango River never reaches the sea: it fans out instead across the Kalahari in one of the world's few great interior deltas, and by a quirk of hydrology its floodwaters arrive in Botswana's dry season, exactly when wildlife needs them most. Plants and animals have synchronised their life cycles to this inverted calendar, which sustains lions, cheetahs, African wild dogs and both black and white rhinoceros. Fittingly, the delta became the 1,000th site inscribed on the UNESCO World Heritage List, in 2014.