The Serengeti is a vast ecosystem in east-central Africa. It spans 30,000 square kilometres (12,000 square miles) and is located in north Tanzania, extending to southwestern Kenya. The name "Serengeti" is derived from the Maasai language and means "endless plains". 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 is home to one of the continent's highest concentrations of large mammal species, including lions, hyenas, zebras, giraffes, and elephants. It also hosts the second largest terrestrial mammal migration in the world, which helps secure it as one of the Seven Natural Wonders of Africa. Approximately 70 large mammal and 500 bird species are found there. This high diversity is a function of diverse habitats, including riverine forests, swamps, kopjes, grasslands, and woodlands. Blue wildebeest, gazelles, zebras, and buffalos are some of the commonly found large mammals in the region. The Serengeti is also renowned for its large lion population and is one of the best places to observe prides in their natural environment. Each year around the same time, the circular great wildebeest migration begins in the Ngorongoro Conservation Area of the southern Serengeti in Tanzania and loops clockwise through the Serengeti National Park and north towards the Masai Mara reserve in Kenya.