The Okavango Delta in Botswana, shown on this 100 m image of 2 April 2014, is a very large inland delta formed where the Okavango River reaches a tectonic trough in the central part of the Kalahari basin. The water reaching the Delta is ultimately evaporated and does not flow into any sea or ocean. Each year, approximately 11 cubic kilometres of water spread over the 6,000-15,000 km² area. Some flood waters drain into Lake Ngami. The Moremi Game Reserve, a National Park, is on the eastern side of the Delta. This statistical significance helped the Okavango Delta secure a position as one of the Seven Natural Wonders of Africa, which were officially declared on February 11, 2013 in Arusha, Tanzania.