Sierra Leone, officially the Republic of Sierra Leone, informally Salone, is a country on the southwest coast of West Africa. It is bordered by Liberia to the southeast and Guinea to the northeast. Sierra Leone has a tropical climate, with a diverse environment ranging from savanna to rainforests, and a total area of 71,740 km2 (27,699 sq mi) and a population of 7,075,641 as of the 2015 census. The capital and largest city is Freetown. Sierra Leone is divided into five administrative regions, which are further subdivided into sixteen districts.