Serengeti National Park, c.5,700 sq mi (14,800 sq km), NE Tanzania, est. 1941. The internationally famous park attracts large numbers of tourists to see the world's largest concentrations of wildebeest and gazelle (which number over 1,000,000 each), as well as large numbers of zebras (200,000) and lions, elephants, and rhinoceros (3,000 each). There are also significant populations of buffaloes, hippopotamuses, giraffes, and hyenas. During the rainy season huge herds of animals migrate across the usually dry and virtually treeless Serengeti in search of grazing land. Animal numbers have increased since the park's inception, especially the number of elephants.