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The Vatican unveiled the largest and most luxurious of the pagan tombs in the necropolis under St. Peter's Basilica on Tuesday after nearly a year of restoration work.

A family of former slaves built the Valeri Mausoleum during the second half of the second century, when Emperor Marcus Aurelius ruled. It is one of 22 pagan tombs in the grottoes under the basilica.

The newly restored tomb was shown to media Tuesday. Visitors can have a guided tour of the grottoes by appointment.

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Emperor Constantine, a convert to Christianity, had the pagan burial grounds covered up in the fourth century so the basilica could be built over the site holding St. Peter's tomb.

The Valeri tomb, made up of several rooms, is several hundred feet from the burial place of the Apostle Peter, venerated by Catholics as the first pope. Peter was martyred in Rome in the area near the Vatican known as Nero's Circus during the first century persecution of Christians by the Romans.

"This restoration takes us straight to the font of the Catholic Church," said Cardinal Angelo Comastri, head of the Fabbrica di San Pietro, the office that for 500 years has been in charge of the running and upkeep of St. Peter's Basilica.

The mausoleum is considered a particularly fine example of the stucco work popular from that era, as well as for the bas reliefs and statues that adorn the tombs.

The tomb tells the history of the family, particularly in bas reliefs, of a girl and a boy from the Caius Valerius Herma family. The children died young, possibly from plague.

Such stuccoed objects as a quill pen and a skein of yarn tell the tale of daily life in the Valeri family. Reliefs of major gods and other pagan figures attest to their strong religious belief.

Several charcoal "graffiti" of designs and Latin inscriptions were left untouched to allow for further research. Scholars think the inscriptions might indicate Peter's tomb.

Once freed, the family of slaves that built the mausoleum amassed a vast fortune.