Located in northern Tanzania, it is the second largest in the country with 14,763 square kilometers. Known for its great annual migration of wildebeest and zebra which, in search of new pastures, move north from their breeding grounds on the fertile southern plains. Many cross the swampy Grumeti River of the western corridor, which is full of crocodiles. Others head northwest toward the Lobo Hills, where the black eagles live. For their part, black rhinos are based in the granite outcrops of Moru Kopjes. It enjoys the reputation of being one of the great wonders of nature in the world. It was declared a Natural Heritage of Humanity in 1981.