France, officially the French Republic, is a member state of the European Union located in its western region, with several overseas territories and islands located on other continents. France is a unitary semi-presidential republic with its main ideals expressed in the Declaration of the Rights of Man and of the Citizen. 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 from the north) by Belgium, Luxembourg, Germany, Switzerland, Italy, Monaco, Spain and Andorra. France's overseas departments and collectivities also share land borders with Brazil and Suriname (bordering French Guiana), and the Netherlands Antilles (bordering Saint-Martin). France is linked to the United Kingdom by the Channel Tunnel, which passes underneath the English Channel. France is the largest state in the European Union by area and the third largest in Europe behind Russia and Ukraine. It would be second if its extra-European territories like French Guiana were included. France has been a major power for many centuries with strong economic, cultural, military and political influence. During the 17th and 18th centuries, France colonised great parts of North America; during the 19th and early 20th centuries, France built the second largest empire of the time, including large portions of North, West and Central Africa, Southeast Asia, and many Pacific islands. France is one of the most developed countries and possesses the fifth largest economy by nominal GDP and seventh largest economy by purchasing power parity. France enjoys a high standard of living as well as a high public education level, it's one of the most globalised nations, has 2009's second best international reputation and has also one of the world's highest life expectancy, with its healthcare system rated as the best in the world. It is the most visited country in the world, receiving 82 million foreign tourists annually. France is one of the founding members of the European Union. It is also a founding member of the United Nations, and a member of the Francophonie, the G8, G20, NATO, OECD, WTO, the Latin Union, and the OSCE. - France is a participating State of the Organization for Security and Cooperation in Europe, which makes its international commitments subject to monitoring under the mandate of the U.S. Helsinki Commission. It is one of the five permanent members of the UN Security Council, possesses the third largest number of nuclear weapons in the world and the largest number of nuclear power plants in the European Union.