The bottom of the Vatican, specifically beneath St. Peter's Basilica, houses the Vatican Necropolis, an ancient Roman cemetery dating back to the 1st through 4th centuries AD. This subterranean area sits at depths of 5 to 12 meters below the modern floor level and contains a series of well-preserved pagan and early Christian tombs. The most significant site within the Necropolis is the Tomb of St. Peter, which tradition holds is the final resting place of the Apostle Peter. Above the Necropolis, but below the main altar, are the Vatican Grottoes, which contain the tombs of many popes, including John Paul II and Benedict XVI. Access to the deepest level, the Scavi (the excavations), is strictly limited to small guided tours of about 250 people per day to preserve the delicate structures. This multi-layered underground world serves as both a historical archaeological site and a sacred pilgrimage destination.