Rwanda, officially the Republic of Rwanda, is a landlocked country in the Great Rift Valley of East Africa, where the African Great Lakes region and Southeast Africa converge. Located a few degrees south of the Equator, Rwanda is bordered by Uganda, Tanzania, Burundi, and the Democratic Republic of the Congo. It is highly elevated, giving it the sobriquet "land of a thousand hills", with its geography dominated by mountains in the west and savanna to the southeast, with numerous lakes throughout the country. The climate is temperate to subtropical, with two rainy seasons and two dry seasons each year. It is the most densely populated mainland African country; among countries larger than 10,000 km2, it is the fifth-most densely populated country in the world. Its capital and largest city is Kigali.