Romania (Romanian: România) is a unitary semi-presidential republic located in Southeastern Europe, bordering the Black Sea, between Bulgaria and Ukraine. It also borders Hungary, Serbia, and Moldova. It covers 238,391 square kilometres (92,043 sq mi) and has a temperate-continental climate. With its 19.94 million inhabitants, it is the seventh most populous member state of the European Union. Its capital and largest city, Bucharest, is the sixth largest city in the EU. The River Danube, which is Europe's second longest river after the Volga, rises in Germany and flows southeastwards for a distance of 2,857 km course through ten countries before emptying in Romania's Danube Delta. Some of its 1,075 km length bordering the country drains the whole of it. The Carpathian Mountains (the tallest peak is Moldoveanu at 2,544 m, 8346 ft) cross Romania from the north to the southwest.