Tsavo National Parks are the oldest and largest parks in Kenya at 11,747 square kilometres. The east park can be accessed by three main gates, from Voi through the Manyani gate, from Mombasa through the Bachuma gate or from Malindi through the Sala gate. There are also several airstrips in the park that allow chartered light planes. Inside the park, the Athi and Tsavo rivers converge to form the Galana River. Most of the park consists of semi-arid grasslands and savanna. It is considered one of the world's biodiversity strongholds, and its popularity is mostly due to the vast amounts of diverse wildlife that can be seen, including the famous 'big five' consisting of masai lion, black rhino, cape buffalo, elephant and leopard. The park also is also home to a great variety of bird life such as the black kite, crowned crane, lovebird and the sacred ibis.The slightly larger Tsavo East is generally flat, with dry plains across which the Galana River flows. Other features include the Yatta Plateau and Lugard Falls. Tsavo West National Park is more mountainous and wetter than its counterpart, with swamps, Lake Jipe and the Mzima Springs. It is known for birdlife and for its large mammals. It is also home to a black rhino sanctuary. Over 500 bird species have been recorded in the area.