Kenya, officially the Republic of Kenya (Swahili: Jamhuri ya Kenya), is a country in Africa with its capital and largest city in Nairobi. Kenya's territory lies on the equator and overlies the East African Rift, covering a diverse and expansive terrain that extends roughly from Lake Victoria to Lake Turkana (formerly called Lake Rudolf) and further south-east to the Indian Ocean. It is bordered by Tanzania to the south and south-west, Uganda to the west, South Sudan to the north-west, Ethiopia to the north and Somalia to the north-east. Kenya covers 581,309 km2 (224,445 sq mi). Kenya's capital and largest city is Nairobi, while its oldest city and first capital is the coastal city of Mombasa.