is a city and special comune (named "Roma Capitale") in Italy. Rome is the capital of Italy and also of the homonymous metropolitan city and of the region of Lazio. With 2.9 million residents in 1,285.3 km2 (496.3 sq mi), it is also the country's largest and most populated comune and fourth-most populous city in the European Union by population within city limits. The urban area of Rome extends beyond the administrative city limits with a population of around 3.8 million. Between 3.2 and 4.2 million people live in the Rome metropolitan area. The city is located in the central-western portion of the Italian Peninsula, within Lazio (Latium), along the shores of Tiber river. Vatican City is an independent country within the city boundaries of Rome, the only existing example of a country within a city: for this reason Rome has been often defined as capital of two states.