St. Peter's Basilica, is a Late Renaissance church located within the Vatican City. St. Peter's Basilica has the largest interior of any Christian church in the world, holding 60,000 people. It is regarded as one of the holiest Christian sites. It has been described as "holding a unique position in the Christian world" and as "the greatest of all churches of Christendom". In Catholic tradition, it is the burial site of its namesake Saint Peter, who was one of the twelve apostles of Jesus and, according to tradition, first Bishop of Rome and therefore first in the line of the papal succession. Tradition and some historical evidence hold that Saint Peter's tomb is directly below the altar of the basilica. For this reason, many Popes have been interred at St Peter's since the Early Christian period.

Originally raised in the Forum Iulium in Alexandria by the Prefect Cornelius Gallus on Augustus's orders around 30–28 BC. Brought to Rome by Caligula in 37 for the spina of the Vatican Circus. Relocated by Pope Sixtus V in 1586 using a method devised by Domenico Fontana; the first monumental obelisk raised in the modern period, it is the only obelisk in Rome that has not toppled since Roman times. During the Middle Ages, the gilt ball on top of the obelisk was believed to contain the ashes of Julius Caesar.Fontana later removed the ancient metal ball, now in a Rome museum, that stood atop the obelisk and found only dust. Pedro Tafur in his Andanças(circa 1440) mentions that many passed between the ground and the "tower" basis "thinking it a saintly thing".

Saint Peter's Square (Italian: Piazza San Pietro) is located directly in front of St. Peter's Basilica in Vatican City, the papal enclave within Rome (the Piazza borders to the East the rione of Borgo). The open space which lies before the basilica was redesigned by Gian Lorenzo Bernini from 1656 to 1667, under the direction of Pope Alexander VII, as an appropriate forecourt, designed "so that the greatest number of people could see the Pope give his blessing, either from the middle of the façade of the church or from a window in the Vatican Palace". The trapezoidal shape of the piazza, which creates a heightened perspective for a visitor leaving the basilica and has been praised as a masterstroke of Baroque theater, is largely a product of site constraints.

Sistine Chapel is the best-known chapel in the Apostolic Palace, the official residence of the Pope in Vatican City. It is famous for its architecture, evocative of Solomon's Temple of the Old Testament, and its decoration which has been frescoed throughout by the greatest Renaissance artists including Michelangelo, Raphael, Bernini, and Sandro Botticelli. Under the patronage of Pope Julius II, Michelangelo painted the chapel ceiling between 1508 and 1512. He resented the commission, and believed his work only served the Pope's need for grandeur. However, today the ceiling, and especially The Last Judgement, are widely believed to be Michelangelo's crowning achievements in painting. The chapel takes its name from Pope Sixtus IV, who restored the old Cappella Magna between 1477 and 1480. Since the time of Sixtus IV, the chapel has served as a place of both religious and functionary papal activity. Today it is the site of the Papal conclave, the process by which a new Pope is selected.

The Cappella Paolina is a famous chapel in the Vatican Palace. It is separated from the Sistine Chapel only by the Sala Regia. The chapel was commissioned in 1538 by the order of Pope Paul III and completed in 1540 under the design and supervision of Antonio da Sangallo the Younger. The Cappella Paolina served as both the Chapel of the Sacrament and the Chapel of the Conclave. Paul III dedicated the chapel to the Feast of the Conversion of St Paul, a festival to which he displayed particular devotion. Michelangelo’s two frescoes in the Cappella Paolina, The Conversion of Saul and The Crucifixion of St Peter were painted from 1542 to 1549. Other paintings in the chapel are by Lorenzo Sabbatini and Federico Zuccari. The statues in the background are by P. Bresciano.

The Vatican Museums, in Viale Vaticano in Rome, inside the Vatican City, are among the greatest museums in the world, since they display works from the immense collection built up by the Roman Catholic Church throughout the centuries. Pope Julius II founded the museums in the 16th century. The Sistine Chapel and the Stanze della Segnatura decorated by Raphael are on the visitor route through the Vatican Museums. The museum has many famous paintings such as Giotto's Stefaneschi Triptych, Raphael's Madonna of Foligno and Transfiguration, Leonardo da Vinci's St. Jerome in the Wilderness, Caravaggio's Entombment, and Perugino's Madonna and Child with Saints. The Collection of Modern Religious Art houses paintings and sculptures from artists like Carlo Carrà and Giorgio de Chirico.