Description & Facts: This is a quick 360 view of St. Peter's Square in Vatican City. The name "Vatican" predates Christianity and comes from the Latin Mons Vaticanus, meaning Vatican Mount. The territory of Vatican City is part of the Mons Vaticanus, and of the adjacent former Vatican Fields where St. Peter's Basilica, the Apostolic Palace, the Sistine Chapel, and museums were built, along with various other buildings. The area was part of the Roman rione of Borgo until 1929. Being separated from the city, on the west bank of the Tiber river, the area was an outcrop of the city that was protected by being included within the walls of Leo IV (847–55), and later expanded by the current fortification walls, built under Paul III (1534–49), Pius IV (1559–65) and Urban VIII (1623–44). When the Lateran Treaty of 1929 that gave the state its present form was being prepared, the boundaries of the proposed territory were influenced by the fact that much of it was all but enclosed by this loop. For some tracts of the frontier, there was no wall, but the line of certain buildings supplied part of the boundary, and for a small part of the frontier a modern wall was constructed. The territory includes St. Peter's Square, distinguished from the territory of Italy only by a white line along the limit of the square, where it touches Piazza Pio XII. St. Peter's Square is reached through the Via della Conciliazione which runs from the Tiber River to St. Peter's. This grand approach was constructed by Benito Mussolini after the conclusion of the Lateran Treaty. According to the Lateran Treaty, certain properties of the Holy See that are located in Italian territory, most notably Castel Gandolfo and the major basilicas, enjoy extraterritorial status similar to that of foreign embassies. These properties, scattered all over Rome and Italy, house essential offices and institutions necessary to the character and mission of the Holy See. Castel Gandolfo and the named basilicas are patrolled internally by police agents of Vatican City State and not by Italian police. St. Peter's Square is ordinarily policed jointly by both.