Sierra Leone (/siːˈɛərə liːˈoʊniː, -liːˈoʊn/ ( listen)), officially the Republic of Sierra Leone, is a country in West Africa. It is bordered by Guinea to the northeast, Liberia to the southeast and the Atlantic Ocean to the southwest. Sierra Leone has a tropical climate, with a diverse environment ranging from savannah to rainforests. The country has a total area of 71,740 km² (27,699 sq mi) and a population of 7,075,641 (based on the 2015 national census). It is a constitutional republic with a directly elected president and a directly elected 112 members of a unicameral legislature known as Parliament.