Rome is a city and special comune in Italy. Rome is the capital of Italy and also of the homonymous province and of the region of Lazio. With 2.7 million residents in 1,285.3 km, 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 Rome metropolitan area. The city is located in the central-western portion of the Italian Peninsula, on the Tiber within Lazio. Rome is the only city in the world to contain in its interior a whole state; the enclave of Vatican City.