The Apostolic Palace (Latin: Palatium Apostolicum; Italian: Palazzo Apostolico) is the official residence of the Pope, which is located in Vatican City. It is also known as the Papal Palace and the Palace of the Vatican. The Vatican itself refers to the building as the Palace of Sixtus V in honor of Pope Sixtus V.
The building contains the Papal Apartments, various government offices of the Catholic Church and the Holy See, private and public chapels, Vatican Museums and the Vatican library, including the Sistine Chapel, Raphael Rooms and Borgia Apartment. The modern tourist can see these last and other parts of the palace, but not many parts, including the Sala Regia and Cappella Paolina. The Scala Regia can be seen into from one end but not entered.(Wikipedia)