African baobab tree (Adansonia digitata) in the Okavango Delta, Botswana. This tree may reach a height of 25m and a diameter of 7 m, and some are believed to be many hundreds of years old (this one allegedly is 4,000 years old). Its bulgy trunk can hold thousands of liters of water for the draught season. The Delta is the dead-end of the Okavango River, whose waters spread along a flat area in the Kalahari Desert, sifting through the sand and evaporating into the air. A wide variety of wildlife resides in this area, including hippos, buffalos, elephants, antelopes and many birds.