Italy officially known as the Italian Republic (Italian: Repubblica Italiana), is a state of Southern Europe and founding member of the European Union. Its capital city is Rome. Italy consists of twenty regions, which encompass almost all of the Italian peninsula and most of the Mediterranean islands surrounding it, including the two largest ones, Sicily and Sardinia. Italy’s northern border is largely defined by the Alps, which separate it from neighbouring France, Switzerland (whose territory includes the Italian exclave of Campione d’Italia), Austria, and Slovenia (proceeding west to east). The Italian peninsula also includes two sovereign states as land-locked enclaves within Italian territory: San Marino and the Vatican City.