Africa, Cape. 4

Southern Africa is a riot of life and colour because of two great ocean currents that sweep around the continent's Cape. To the east, the warm Agulhas current, generating clouds that roll inland to the wettest place in southern Africa. To the west is the cold Benguela current, home to more great white sharks than anywhere else. Moisture-laden fog rolls inland, supporting wonderful desert garden. And where the two currents meet, the clash of warm and cold water creates one of the world's most fabulous natural spectacles: South Africa's sardine run. This is the greatest gathering of predators on the planet, including Africa's largest, the brydes whale.