These pools are the remnant ox-bow lakes that the Zambezi River carved out thousands of years ago as it changed its course northwards. Hippopotamus, crocodiles and a wide variety of aquatic birds are associated with the pools. ''Long Pool'', is the largest of the four pools, extending some six kilometers in a west-east direction. This pool has a large population of hippo and crocodiles and is a favourite for the large herds of elephant that come out of the thickly vegetated areas in the south to drink.