Coordinates: 51°N 9°E / 51°N 9°E / 51; 9 Germany (German: Deutschland, German pronunciation: [ˈdɔʏtʃlant]), constitutionally the Federal Republic of Germany (German: Bundesrepublik Deutschland, listen (help·info)), is a country in Central and Western Europe, lying between the Baltic and North Seas to the north and the Alps, Lake Constance, and the High Rhine to the south. It borders Denmark to the north, Poland and the Czech Republic to the east, Austria and Switzerland to the south, France to the southwest, and Luxembourg, Belgium, and the Netherlands to the west. Germany includes 16 constituent states, covers an area of 357,386 square kilometres (137,988 sq mi), and has a largely temperate seasonal climate. With 83 million inhabitants, it is the second most populous state of Europe after Russia, the most populous state lying entirely in Europe, as well as the most populous member state of the European Union. Germany is a very decentralised country. Its capital and largest metropolis is Berlin, while Frankfurt serves as its financial capital and has the country's busiest airport. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity. A region named Germania was documented before AD 100. Beginning in the 10th century, German territories formed a central part of the Holy Roman Empire. During the 16th century, northern German regions became the centre of the Protestant Reformation. After the collapse of the Holy Roman Empire, the German Confederation was formed in 1815. The German revolutions of 1848–49 resulted in the Frankfurt Parliament establishing major democratic rights. In 1871, Germany became a nation state when most of the German states unified into the Prussian-dominated German Empire. After World War I and the revolution of 1918–19, the Empire was replaced by the parliamentary Weimar Republic. The Nazi seizure of power in 1933 led to the establishment of a dictatorship, World War II, and the Holocaust. After the end of World War II in Europe and a period of Allied occupation, two new German states were founded: West Germany and East Germany. Following the Revolutions of 1989 that ended communist rule in Central and Eastern Europe, the country was reunified on 3 October 1990. Today, the sovereign state of Germany is a federal parliamentary republic led by a chancellor. It is a great power with a strong economy; it has the world's fourth-largest economy by nominal GDP, and the fifth-largest by PPP. As a global leader in several industrial and technological sectors, it is both the world's third-largest exporter and importer of goods. As a highly developed country with a very high standard of living, it offers social security and a universal health care system, environmental protections, and a tuition-free university education. The Federal Republic of Germany was a founding member of the European Economic Community in 1957 and the European Union in 1993. It is part of the Schengen Area and became a co-founder of the Eurozone in 1999. Germany is also a member of the United Nations, NATO, the G7, the G20, and the OECD. Known for its long and rich cultural history, Germany has continuously been the home of influential people in the arts, sciences and humanities. Germany has many World Heritage sites and is among the top tourism destinations in the world.