Cinecittà is Italy's foremost film studio, founded in 1937 by Mussolini and used for many iconic Italian and international films. It's possible to take a tour of the studios (Cinecittà Si Mostra, or Cinecittà Shows Off), where you get to visit several impressive sets, including 1500s Florence and ancient Rome, and there are interesting exhibitions, one dedicated to the work of Federico Fellini, and another exploring the studio's history. Of the thousands of films shot here, almost 50 have won Oscars.
Originally intended by Mussolini to turn out propaganda pictures, the studios were used during WWII variously as a refugee camp and hospital, but postwar they went from strength to strength. In the 1950s many major Hollywood films were made here, including Cleopatra, and Rome earned the nickname Hollywood on the Tiber. This was also to become Fellini's stomping ground – he even had a bedroom here – and La Dolce Vita was filmed in Theatre 5, within which the director recreated Via Veneto. Later, spaghetti westerns dominated the schedule. Recently it was used for the HBO series Rome and Paolo Sorrentino's The Young Pope.
At certain times guided tours of the sets are offered in English; check the website.
Note, movie-themed amusement park Cinecittà World is located 25km southwest of Rome.