Germany, officially the Federal Republic of Germany, is a country in Western and Central Europe. It lies between the Baltic Sea and the North Sea to the north with the Alps to the south. Its sixteen constituent states have a total population of over 82 million, making it the most populous member state of the European Union (EU). Germany borders Denmark to the north; Poland and the Czech Republic to the east; Austria and Switzerland to the south; and France, Luxembourg, Belgium, and the Netherlands to the west. The nation's capital and most populous city is Berlin and its main financial centre is Frankfurt; the largest urban area is the Ruhr.