Archaeologists have uncovered a hidden underground chamber beneath Hadrian's Villa in Tivoli, Italy, which researchers say could be the oldest structure ever identified at the famous imperial site. The discovery, announced by Pablo de Olavide University in Seville, Spain, matters because it points to an earlier villa that predated Emperor Hadrian's residence and was partially absorbed into his sprawling complex, offering rare clues about a period largely erased by the later construction.

The chamber dates to the Roman Republic period (509 B.C. to 27 B.C.), centuries before Hadrian ruled Rome from 117 to 138 A.D. Officials believe the abandoned structure may have served as a silo or storage facility, and it was found partially filled with ancient construction debris and ceramic materials. Rafael Hidalgo, director of the Palazzo Project at the villa, said it was surprising that the structure was not completely filled with soil. Hadrian's Villa is a UNESCO-listed site, and its namesake emperor is best known for building Hadrian's Wall in northern Britain.