As of Jan. 1, 2016, the province of Rome is officially called Città Metropolitana di Roma Capitale. The provincia di Roma is one of five provinces that together make up the regione Lazio (Latium). The other four are Viterbo, Rieti, Latina and Frosinone. With its over four million inhabitants, it is the biggest one of the whole of Italy.
Province of Rome
Main places to visit

The capital of this most populous province in Italy is of course Rome itself. With the capital included, the province consists of a total of 121 municipalities.
The most popular day trips from Rome are Tivoli and the Castelli Romani, a group of small towns more or less centered around Lake Albano. Cerveteri is known for its Etruscan ruins and Subiaco for its ancient abbeys.
Civitavecchia is the cruise ship harbor of Rome.
Anzio is the best known beach town, but is more famous as the Allied forces’ landing site in World War II.
Castelli Romani
The Castelli Romani are situated in an area known as the Colli Albani (“Alban Hills”). The most interesting towns are Frascati, Grottaferrata, Ariccia and Castel Gandolfo. The Pope has his summer residence in the latter, which means that on Sundays it can be quite busy.
Subiaco and surroundings
Subiaco is one of the most important pilgrim’s destinations near Rome. Affile is one of the more interesting towns in the vicinity.