The temple, thought to be about the size of London's St. Paul's Cathedral, is a few feet below the surface at a place called Falerii Novi, which is about 30 miles north of Rome. The temple is thought to have been nearly 400 feet long and 200 feet wide. The dig has turned up columns on three sides of the temple.

The site is thought to have been active during the era of the Roman Republic, so in the 3rd and 4th centuries B.C. Population estimates for that time period are about 2,500.

The archaeologists mounted a radar scanner on the back of a quad bike; as well, they used magnetometry to detect metals at greater depths than can metal detectors.

The find is the latest in a series of excavations at the site, which was first worked on in the 1990s. Also found have been evidence of a forum, a theater, shops, warehouses, and temples.

Romans founded the town after 241 B.C., as a means of dealing with a revolt by one of the Falisci tribes, who resisted the might of Rome for a long time and sometimes allied themselves with the Etruscans.