Thirty feet below a busy train station in Rome, an ancient basilica was discovered by accident about a hundred years ago. The structure under the Termini Station, which recently opened to the public, features more than 20 fully restored stucco artworks.

The basilica, the oldest of its kind, dates back about 2,000 years to the era of Rome's first emperor, Augustus. The powerful family that built it, one theory goes, was not in favor with later emperors, so the structure was filled in with dirt and abandoned, CBS News correspondent Seth Doane reports.

It was found by a railway line worker digging a hole, said Luca Del Fra with Rome's cultural heritage bureau.

"A worker for the railway line put their head inside and saw all of this," he said.

Restorers have been working to clean the ancient stucco artwork and uncover clues that might reveal what the building was used for — perhaps an ancient tomb or a place for pagan rites.

"We are in a very mysterious place," restorer Laura Lippi said.

A 2,000-year-old basilica found beneath Rome's Termini train station has been restored. CBS News

Over the centuries, dirt and calcium carbonate caked over the stucco, covering the ancient figures depicting then-everyday life. But that layer of grime also protected the artwork.

"It seems incredibly difficult to remove this darker calcium carbonate but not affect the art and such below," Doane said.

"That is the reason why the laser technology was so important to us," Lippi said. "We take care of art in a sort of surgical way."

The Termini Station isn't the only train stop to provide a peek into the city's ancient history. Part of the San Giovanni metro stop has a museum with several subway-excavation discoveries.