France is a unitary semi-presidential republic located mostly in Western Europe, with several overseas regions and territories. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean. From its shape, it is often referred to in French as l’Hexagone ("The Hexagon"). France is the largest country in Western Europe and the third-largest in Europe as a whole. It possesses the second-largest exclusive economic zone in the world. France has been a major power with strong cultural, economic, military, and political influence in Europe and around the world. France has its main ideals expressed in the 18th-century Declaration of the Rights of Man and of the Citizen. From the 17th to the early 20th century, France built the second-largest colonial empire of the time, ruling large portions of first North America and India and then Northwest and Central Africa; Madagascar; Indochina and southeast China; and many Caribbean and Pacific Islands.