Mission: Impossible III was filmed in Italy
St Peter's Square
In movie
Scene where Declan arrives at the Vatican for the mission.
Real
Scene was shot Saint Peter's Square is a large plaza located directly in front of St. Peter's Basilica in Vatican City, the papal enclave inside Rome. Both the square and the basilica are named after Saint Peter, an apostle of Jesus considered by Catholics to be the first Pope.
Vatican
St. Peter's Square
Tiber
In movie
Scene where The team race down the Tiber River in a speedboat after their successful mission at the Vatican.
Real
Scene was shot A close look at the scene reveals that the team's boat ride is a little bit odd.
In fact, the boat first passes the Pont Sant'Angelo and then the Ponte Umberto I, near Corte di Cassazione. Totally fine, but at the end of the scene, they race between the Ponte Sant'Angelo and the Ponte Umberto I again.
Rome