A man walks with donkeys on September 30 at a Maasai village at the foot of the mountain, El-Doinyo Lengai, in Tanzania. The name means Mountain of God in the local Maa language. The mountain is an active volcano and it is Lake Natron’s closeness to the volcano which accounts for the caustic nature of the water. It is this corrosive quality which keeps predators away from the flamingos. They typically lay one egg on a small mound of mud on the dried out parts of the lake.