The dead Camelthorn trees on the Savuti Marsh have become one of the most prominent features of the landscape – skeletons of trees drowned in the flood-waters at least 40 years ago. The shallow basin of the Mababe Depression is now the waterless bed of an ancient lake and the marsh itself is grassland that is home to large numbers of animals. The western edge of Savuti is formed by the Magwikhwe sand ridge, which is approximately 100 km long and 20 m high. This is the ancient shoreline of a super-lake that once covered most of Northern Botswana. It is hard to imagine that this harsh, dry landscape was once submerged under an enormous inland sea. Another part of the Savuti is characterised by the Gubatsa Hills, which were formed millions of years ago during volcanic movement. These hills rise to a height of about 90 meters out of an otherwise completely flat landscape.