Vatican Grottoes

The Vatican Grottoes form the lower level immediately beneath the floor of St. Peter’s Basilica. Their present structural core consists of vaults built in 1590–1591 to support the Renaissance church, although the official basilica history traces the idea of the lower space to an earlier design change proposed by Antonio da Sangallo the Younger after Raphael’s death in 1520.

Pope Clement VIII expanded and reorganized the area in 1592, including work around the older crypt near the tomb venerated as that of Saint Peter. Under Paul V, new corridors and chapels were added in 1616–1617. As the last parts of the old basilica were demolished, the grottoes also became a place for preserving monuments, mosaics, paintings and inscriptions from the earlier church.

Further devotional chapels and papal tombs were added over later centuries. The grottoes therefore combine structural, memorial and religious functions. They are closely connected with Catholic devotion to Saint Peter and with remembrance of popes and saints buried in the complex, but they do not have a separate apparition or miracle tradition that needs to be asserted.

The area lies within the Vatican City UNESCO World Heritage property. Current official visitor information states that the grottoes are free to enter daily from 09:00 to 18:00 and that photography is forbidden.