The Serengeti ecosystem is a geographical region in Africa, spanning the Mara and Arusha Regions of Tanzania. The protected area within the region includes approximately 30,000 km² (12,000 sq mi) of land, including the Serengeti National Park and several game reserves. The Serengeti hosts the second largest terrestrial mammal migration in the world, which helps secure it as one of the Seven Natural Wonders of Africa.