St. Peter's Basilica (Italian San Pietro in Vaticano) is a major basilica in Vatican City, an enclave of Rome. St. Peter's was until recently the largest church ever built (it covers an area of 23,000 m² and has a capacity of over 60,000), and it remains one of the holiest sites in Christendom. Ancient tradition has it that St. Peter's Basilica was built at the place where Peter, the apostle who is considered the first pope, was crucified and buried; his tomb is under the main altar. Other popes are also buried in and below the basilica. Contrary to what one might reasonably assume, St. Peter's is not a cathedral - the pope's cathedral is St. John Lateran. The current location of St. Peter's Basilica is the site of the Circus of Nero in the first century AD. After Emperor Constantine officially recognized Christianity he started construction (in 324) of a great basilica in this exact spot, which had previously been a cemetery for pagans as well as Christians. In the mid-15th century it was decided that the old basilica should be rebuilt. Pope Nicholas V asked architect Bernardo Rossellino to start adding to the old church. This was abandoned after a short while, but in the late 15th century Pope Sixtus IV had the Sistine Chapel started nearby. Construction on the current building began under Pope Julius II in 1506 and was completed in 1615 under Pope Paul V. Donato Bramante was to be the first chief architect. Many famous artists worked on the "Fabbrica di San Pietro" (as the complex of building operations were officially called). Michelangelo, who served as main architect for a while, designed the dome, and Bernini designed the great St. Peter's Square. The following description is a virtual tour that follows this basic path: views from afar; St. Peter's Square; exterior of St. Peter's Basilica; nave; right aisle and transept; dome area with baldacchino; cathedra of St. Peter; left transept and aisle; and crypt/grottoes. See our St. Peter's Basilica Photo Gallery for a visual tour. St. Peter's Square Providing a fitting approach to the great church is the huge, elliptical St. Peter's Square (Piazza San Pietro), designed by Bernini and built between 1656 and 1667. There are two beautiful fountains in the square, the south/left one by Carlo Maderno (1613) and the northern/right one by Bernini (1675). In the center of the square is a 25.5-meter-tall obelisk, which dates from 13th-century BC Egypt and was brought to Rome in the 1st century to stand in Nero's Circus some 275 yards away. It was moved to its present location in 1585 by order of Pope Sixtus V. The task took four months and is said to have been done in complete silence on pain of death. If you include the cross on top and the base, the obelisk reaches 40m. The square is outlined by a monumental colonnade by Bernini, its open arms symbolically welcoming the world into the Catholic Church. Between the obelisk and each fountain is a circular stone that marks the focal points of an ellipse. If you stand on one of these points, the two rows columns of the colonnade line up perfectly and appear to be just a single row. On top of the colonnade are 140 statues of saints, crafted by a number of sculptors between 1662 and 1703. To the right of the southern gate of the colonnade is St. Macrina, grandmother of the Cappadocian fathers, followed by some founders of religious orders: St. Dominic, St. Francis, St. Bernard, St. Benedict, and St. Ignatius of Loyola. Some of the apostles are at the far end of the colonnade, outside the square and down the street: look for Paul and John on the south side (on the left as you walk to the square). More details here. Near the stairs to the basilica at the front of the square are colossal statues of Sts. Peter and Paul, the patron saints of Rome. These were ordered by Pope Pius IX on Easter 1847, who wanted to replace the existing smaller ones. The new statues had been commissioned bythe previous pope for St. Paul Outside the Walls. Peter was sculpted by Giuseppe De Fabris in 1838-40 and stands 5.55m in height, on a pedestal 4.91m high. Paul was sculpted in 1838 by AdamoTadolini, and is also 5.55m in height, on a pedestal 4.91m high. Exterior of St. Peter's Basilica The dome of St. Peter's was designed by Michelangelo, who became chief architect in 1546. At the time of his death (1564), the dome was finished as far as the drum, the base on which domes sit. The dome was vaulted between 1585 and 1590 by the architect Giacomo della Porta with the assistance of Domenico Fontana, who was probably the best engineer of the day. Fontana built the lantern the following year, and the ball was placed in 1593. The great double dome is made of brick and is 42.3 metres in interior diameter (almost as large as the Pantheon), rising to 120 metres above the floor. In the early 18th century cracks appeared in the dome, so four iron chains were installed between the two shells to bind it. The four piers of the crossing that support the dome are each 60 feet (18 meters) across. Uniquely, Michelangelo's dome is not a hemisphere, but a parabola: it has a vertical thrust, which is made more emphatic by the bold ribbing that springs from the paired Corinthian columns, which appear to be part of the drum, but which stand away from it like buttresses, to absorb the outward thrust of the dome's weight. Above, the vaulted dome rises to Fontana's two-stage lantern, capped with a spire. The grand façade is 116 m wide and 53 m high. Built from 1608 to 1614, it was designed by Carlo Modeno. The central balcony is called the Loggia of the Blessings, and is used for the announcement of the new pope with "HabemusPapum" and his UrbietOrbi blessing. The relief under the balcony, by Buonvicino, represents Christ giving the keys to St. Peter. The facade is topped by 13 statues in travertine. From left, the statues represent: Thaddeus, Matthew, Philip, Thomas, James the Elder, John the Baptist, Christ the Redeemer (in the center), Andrew, John the Evangelist, James the Younger, Bartholomew, Simon and Matthias. St. Peter's statue in this set is inside. Two clocks are on either side; the one on the left is electrically operated since 1931, with its oldest bell dating to 1288. Stretching across the facade is the dedicatory inscription: IN HONOREM PRINCIPIS APOST PAVLVS V BVRGHESIVS ROMANVS PONT MAX AN MDCXII PONT VII (In honor of the prince of apostles; Paul V Borghese, pope, in the year 1612 and the seventh year of his pontificate) Between the façade and the interior is the portico. Mainly designed by Maderno, it contains an 18th century statue of Charlemagne by Cornacchini to the south, and an equestrian sculpture of Emperor Constantine by Bernini (1670) to the north.。