Vatican City
The Vatican City is the world's smallest country both by area and by population, and is the center of Catholicism. As a district of Rome, it encompasses the Vatican City State (Italian: Stato della Città del Vaticano; Latin: Status Civitatis Vaticanae), as well as the surrounding Roman neighborhoods of Borgo and Prati. St. Peter's Basilica, the Vatican Museums and the Sistine Chapel are all in Vatican City.