France ( or ; ), officially the French Republic (, ), is a country whose metropolitan territory is located in Western Europe and that also comprises various overseas islands and territories located in other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean. It is often referred to as "L’Hexagone" ("The Hexagon") because of the shape of its territory. France is a unitary semi-presidential republic with its main ideals expressed in the Declaration of the Rights of Man and of the Citizen.