Vatican archaeology: Digging history beneath St. Peter's

The oldest burial chamber found during the excavation beneath St. Peter's in Rome, 1950. (Nat FarbmanTime & Life Pictures/Getty Images)

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 FarbmanTime & Life Pictures/Getty Images)

Scene during the excavation beneath St. Peter's in Rome, 1950. (Nat FarbmanTime & Life Pictures/Getty Images)

Tomb of the Egizio featuring elaborate sarcophagi sculpted with scenes of Bacchic rites. While most of the findings here were purely pagan, there were also Christian designs -- for example, of a palm leaf and a dove. (Nat FarbmanTime & 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 FarbmanTime & Life Pictures/Getty Images)

Classic sculpture adorns the Marci sarcophagus of Q. Marcius Hermes and his wife. <a href="http://life.time.com/culture/the-vatican-unearthing-history-beneath-st-peters-1950-photos/#1">See tons of other pics from the excavation at Life.com</a>. (Nat FarbmanTime & Life Pictures/Getty Images)