Although Etosha is most famous for its diverse wildlife, which includes almost the entire spectrum of African big game as well as more than 300 bird species, the 4760 km² large salt pan, with its eerie atmosphere of desolation, attracts a great number of visitors, too. Most of the time a dry, flat expanse of glistening white, after strong rains it still reminds of its former glory, when the area was covered by a lake that, if it existed today, would be the third largest in the world. A number of springs occur along the southern margin of Etosha Pan, which provide water for the Park’s wildlife during the long dry season, and make for great game viewing during the hours of dawn and dusk. The life-sustaining water originates from the dolomites of the Otavi Mountainland to the south, where karst structures like Lake Otjikoto provide ample mobility for groundwater; where the saturated carbonate rocks are in contact with the clay-rich and impermeable sediments of the younger Kalahari Group, the water rises to the surface to form springs.