Two million years ago the Okavango river flowed into the Limpopo and emptied into the Indian Ocean, but the faults created by tectonic movement diverted the river from its original course. The river that never finds the sea” now ends in Botswana, in a vast interior delta of 9,300 square miles (15,000 km2) at the entrance of the Kalahari Desert. This labyrinth of swamps is home to 400 species of birds, 95 reptiles and amphibians, 70 fish, and 40 large mammals. Hidden in the islets of vegetation where they find food and protection from predators, lechwe (Kobus leche)—an antelope typical of swampy environments—exist in abundance in the waters of the Okavango delta. Since 1996 the Okavango Delta has been protected by the Ramsar Agreement, which concerns 1,075 wet zones of international importance throughout the world.