The Federal Republic of Germany lies at the heart of Europe, bounded by the Netherlands, Belgium, Luxembourg and France to the west, Switzerland and Austria to the south, and, to the east, the Czech Republic and Poland. Germany also has a short border with Denmark to the north, separating its North Sea and Baltic Sea coastlines. After losing around a third of its eastern territory at the end of world war two, the country was split for four decades into the distinct political and geographic entities of East and West Germany. The two halves were reunited in 1990, and Germany is now the fourth largest country by area (357,021 square kilometres) in the European Union. It is divided into 16 federal states known as Länder, ranging from large regions such as Bavaria and Lower Saxony to smaller city states, including Hamburg and Berlin.