Unearthing history beneath St. Peter's Basilica

The tomb of the Caetennii (17 x 18 feet) was one of the richest and most lavishly decorated of all those excavated beneath St. Peter's. ( Nat Farbman—Time & Life Pictures/Getty Images)

Workmen examining underneath the floor of Basilico. ( Nat Farbman—Time & Life Pictures/Getty Images)

Pope Pius XI, whose desire to be buried below St. Peter's nave led to the historic excavations, lies in his stone sarcophagus in renovated upper grottoes. (Nat Farbman—Time & Life Pictures/Getty Images)

The interior of St. Peter's basilica, with markers indicating the location of the excavation beneath the floor, 1950. (Nat Farbman—Time & Life Pictures/Getty Images)