France, officially the French Republic (French: République française, pronounced: [ʁepyblik fʁɑ̃sɛz]), is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. 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 geometric shape of its territory. It is bordered (clockwise starting from the northeast) by Belgium, Luxembourg, Germany, Switzerland, Italy and Monaco; with Spain and Andorra to the south. France is linked to the United Kingdom by the Channel Tunnel, which passes underneath the English Channel. In addition to these borders on the European continent France has land borders with Suriname and Brazil through French Guiana, as well as with the Netherlands through the Collectivity of Saint Martin. It is the largest west-European country and it possesses the second-largest Exclusive Economic Zone in the world, covering 11,035,000 km2 (4,260,000 sq mi), just behind that of the United States (11,351,000 km2 / 4,383,000 sq mi).