This book provides a scholarly account of pre-Christian and the post-Christian history of that portion of the Vatican Hill upon which St. Peter's stands, and her description of the scientific investigation of the space beneath the high altar, the traditional burial place of St. Peter, which was undertaken with the authority of the late Pope, Pins XII. Professor Guarducci notes the disinclination to explore this site felt by all former ages. "An irresistible prudence, almost an unconquered fear, prevented a thorough investigation of the terrain," she writes. "The fear of finding something down there which would contradict or modify the tradition dear to the faithful overcame the desire to appease a burning curiosity."The satisfaction of this "burning curiosity" has, it is true,modified the popular conception of the Apostle's tomb, but it has not contradicted the tradition.A visit to the street of tombs in the ancient Roman cemetery upon which St. Peter's is built (it is thirty feet beneath the nave and the high altar), is the most impressive and memorable experience that can fall to the lot of anyone in Rome.The excavations are not open to the public, and entry willalways be restricted to small groups of scholars, historians and archaeologists. The visitor descends a flight of steps at the Arco delle Campane entrance (on the extreme left as you face St.Peter's) and these lead beneath the Vatican Grottoes into a dusty silent Roman street which might be in Herculaneumor Pompeii. Sombre and dignified brick doorways, standing on each side of the road, afford entry into painted tomb chambers where the dead still lie in sarcophagi or in urn burials. This cemetery, which was used by both pagans and Christians, was once open to the sun and air, but has known no daylight since Constantine the Great built the basilica upon it sixteen centuries ago. Now, by the stark light of unshaded electric bulbs, and beneath a roof of iron and steel, the visitor explores this street, reading the names of those buried there so long ago, until he comes to that space below the high altar which archaeologists can recognize as the tomb, or the memorial, of St. Peter. To the layman, it is a scene of some confusion where walls of different dates, and marble coffins embedded in masonry, are crowded together side by side, and only the trained eye can detect the essential pattern. The visitor can only reflect with awe that he is standing in a place venerated by Christians since the first century.The visible evidence of such veneration is the theme of this fascinating book.