Etosha is the floor of a lake that lost its river: 4,800 square kilometres of white salt in northern Namibia, flat and bright enough to be picked out from orbit. The Kunene used to feed it. The land tilted, the river turned west for the Atlantic instead, and what had been a lake dried down to crust. Nothing drains out of the basin now, so anything that reaches it stays until it evaporates. That dryness is what makes the park around it work. With water in only a few places, you do not go looking for animals; you park at a busy waterhole and let the day come to you. Through the worst of the midday heat the elephants file in to drink and jostle, and straight-horned oryx, zebra and giraffe edge up behind them for a turn. The springbok are the nervous ones, inching forward with one eye on the bush, and now and then a herd breaks into pronking, stiff-legged jumps straight up off the ground.
After dark the cast changes. Every rest camp has a floodlit waterhole beside it, and from the low wall you watch black rhino step carefully out of the dark, elephants drink in near silence, sometimes a lion come down. Etosha holds more of these rhino than any other reserve in Africa. Away from the water, where the grassland opens flat to the horizon, wildebeest and zebra resolve out of the shimmer in loose herds with the white pan laid out behind them. Every few years the rains are heavy enough to put a few centimetres of water back on that pan, and flamingos arrive in their tens of thousands to breed, more than a million birds in the best of those years. Most years it stays a dry white crust, and it gets carried around the park instead. The elephants that come in to drink are chalk-pale from head to foot, having blown the old lake bed over themselves to keep the insects off.