Vatican Grottoes

The Vatican Grottoes lie beneath the central nave of St. Peter's Basilica, between the floor of the Constantinian basilica and the present one. Excavations made there under Pius XII showed that the original St. Peter's Basilica was not built on Nero's circus, but on a pre-Costantinian necropolis. The grottoes contain the tombs of popes (notably that of Boniface VIII) and the pre-Constantinian necropolis. 

The New Grottoes (so-called because they are of more recent construction and cannot normally be visited), extend around the chapel of St. Peter, which was built over the tomb of the apostle and is known also as the "Clementine chapel", as it was richly ornamented in the time of Clement VIII. 

The Old Grottoes can be visited by descending from the basilica down a narrow staircase under one of the pillars of the dome, and date back to 1606, when Paul V ordered the demolition of the front of the old basilica. They are composed of 3 naves beneath the central nave of the Vatican basilica. They house the tombs of many popes who wanted to be buried near the tomb of St. Peter. There is the tomb of Boniface VIII, with the figure of the pope lying on a draped urn, and those of Benedict XV, Pius XI, Pius XII, Paul VI and John Paul I. There are also the tombs of some rulers, including Queen Christina of Sweden and the Queen of Cyprus.