For 10 points, name this world's smallest country located entirely within the city of Rome.
This country was officially recognized in the Lateran Treaties of 1929. It has extraterritorial authority over Castel Gandolfo. Places of interest in this country include the Sistine Chapel and Saint Peter's Square and Basilica. Voting in this country is restricted to Cardinals under eighty years old. For 10 points, name this world's smallest country located entirely within the city of Rome.
This country was officially recognized in the Lateran Treaties of 1929.
State of the {Vatican City} [accept {Holy See;} accept {Santa Sede;} accept {Stato della Citta} del {Vaticano}]