Italy, is a country consisting of a peninsula delimited by the Alps and several islands surrounding it. Italy is located in the center of the Mediterranean Sea, in Southern Europe, and is also often considered part of Western Europe. A unitary parliamentary republic with Rome as its capital and largest city, the country covers a total area of 301,340 km2 (116,350 sq mi) and shares land borders with France, Switzerland, Austria, Slovenia, and the enclaved microstates of Vatican City and San Marino. With around 60 million inhabitants, Italy is the third-most populous member state of the European Union, after Germany and France. Due to its central geographic location in Southern Europe and the Mediterranean, Italy has historically been home to myriad peoples and cultures. Over 35% of the Italian territory is mountainous.[171] The Apennine Mountains form the peninsula's backbone, and the Alps form most of its northern boundary, where Italy's highest point is located on Mont Blanc (Monte Bianco) (4,810 m or 15,780 ft). The Po, Italy's longest river (652 kilometres or 405 miles), flows from the Alps on the western border with France and crosses the Padan plain on its way to the Adriatic Sea. The largest lake is Lake Garda (367.94 km2 or 142 sq mi)