Mauritania, officially the Islamic Republic of Mauritania, is a sovereign country in Northwest Africa. It is bordered by the Atlantic Ocean to the west, Western Sahara to the north and northwest, Algeria to the northeast, Mali to the east and southeast, and Senegal to the southwest. By land area, Mauritania is the 11th-largest country in Africa and the 28th-largest in the world, and 90% of its territory is situated in the Sahara. Most of its population of approximately 4.3 million lives in the temperate south of the country, with roughly one-third concentrated in the capital and largest city, Nouakchott, located on the Atlantic coast.