Archaeologists Discover Details of Buried Roman City Without Digging

Ground-penetrating radar revealed Falerii Novi’s elaborate architecture, including a bath complex, theater and network of water pipes

GPR Image of Falerii Novi's Temple
Ground-penetrating radar map of the newly discovered temple in Falerii Novi, Italy L. Verdonck

Rome wasn’t built in a day, and, apparently, neither was Falerii Novi. Thanks to new radar imaging technology, researchers have uncovered the buried remains of this intricately planned, walled Roman city without lifting a single shovel.

As detailed in the journal Antiquity, archaeologists from the University of Cambridge and Ghent University mapped the complete ancient city using ground-penetrating radar (GPR). Just as X-rays can reveal skeletal damage without doctors needing to cut open a patient, GPR uses radio waves that enable researchers to explore covered ruins without excavating.

The technology’s radar antenna sends radio signals into the ground, where waves bounce off of solid objects, explains Will Dunham for Reuters. “Echoes” from these waves are then recorded as images.

“The astonishing level of detail which we have achieved at Falerii Novi, and the surprising features that [GPR] has revealed, suggest that this type of survey could transform the way archaeologists investigate urban sites, as total entities,” says study author Martin Millett, an archaeologist at the University of Cambridge, in a statement.

Located some 30 miles north of Rome, Falerii Novi existed as an active urban center from 241 B.C. to around 700 A.D. The site is ideal for using GPR, as little of it has been excavated, and no new structures have been built over its roughly 75 acres (about half the size of the famed Pompeii). To survey the area, researchers spent upward of four months pulling GPR equipment across the surface with an all-terrain vehicle, reports Reuters.

Ruins of Buried Roman City
Present-day remains at the buried ancient Roman city of Falerii Novi Mongolo1984 via Wikimedia Commons under CC-BY-SA-4.0

Detailed images of the city revealed a large public bath house, a theater, a market and a temple—features far more elaborate than the team had expected to find. One of Falerii Novi’s most notable elements was its carefully planned water system, Millet tells the Guardian’s Esther Addley. Rather than running in a network along the streets as in other cities of the time, the town’s water pipes were laid out beneath its buildings before they were erected, suggesting significant foresight in city planning.

Historic site excavations such as those conducted at the Pompeii Archaeological Park can be costly and time-consuming. These projects also incur the possibility of damaging irreplaceable structures and artifacts.

Using GPR, researchers now have the ability to identify if, where and how eventual digging should occur. The technology may also provide archaeologists with critical information that would be overlooked in traditional excavations.

Millet tells CNN’s Ashley Strickland that GPR, while often employed as a “prospecting method” for identifying forgotten structures, is actually “better attuned to exploring known sites in great detail.”

Still, the tool has its downsides—including the amount of time required to analyze data. Processing a 2.5-acre section takes 20 hours, reports CNN. The researchers are still working through the Falerii Novi data, but they expect to complete the project within the next year.

At Falerii Novi, the team was especially surprised to find a route circling the city. Millet and his colleagues hypothesize that the path was used in a religious procession leading to what the archaeologist describes as a “big and spectacular” monument. The path was “unlikely to have been uncovered by excavation alone,” according to the Guardian, and Millet says no one he’s shown the nearly 200-foot long monument to knows what it is.

The researcher’s comment highlights a challenge that even new technologies can’t fully address: While the successful application of GPR at Falerii Novi proves that high-resolution mapping can be an invaluable tool for visualizing history, archaeologists are still left with the heady task of interpreting what they see.