From The History blog:
On the night of Tuesday, October 16th, 25-year-old bartender Mirko Curti left his apartment building at 196 Via di Pietralata in the Tiburtina neighborhood of Rome with his friend Raimondo Turnu in search of a missing cat. They heard meowing and followed the sound to an aperture that, due to heavy rains, had recently appeared in a low volcanic tufa cliff nearby. It was the entrance to a cave. Inside they found a number of human bones and a wall of niches called a columbarium which once held the ashes of Roman dead. “It was impressive,” said Curti. “I felt like an explorer. You go behind your house and you end up feeling like Indiana Jones.”
You might think this sort of thing happens all the time in a city as ancient and layered as Rome, but it really doesn’t, hence their elation. Tiburtina is within the current boundaries of the city, not in the historic center. It’s a relatively modern residential neighborhood, outside of the pomerium, the ancient sacred boundary that marked what was Rome and what was just land Rome owned. It was prime real estate for burials, though, since by law people could not be buried inside the pomerium. Plenty of archaeological finds have been made in the area (especially along the ancient Roman road), but you wouldn’t expect to stumble on one while looking for your cat behind your building.
Read the rest there.