Buried Roman city mapped by technique set to revolutionise archaeology

An entire buried Roman city half the size of Pompeii has been mapped for the first time in astonishing detail by a technique of ground penetrating radar (GPR) that is set to revolutionise archaeology.

Without even wielding a trowel, archaeologists from the universities of Cambridge and Ghent were able to reveal the glories of Falerii Novi, located 50km north of Rome, despite the city remaining deep underground.

In a paper published today in the journal Antiquity, archaeologists’ write how they used new advances in GPR to reveal surprisingly rich architectural refinement in Falerii Novi, which is located within a walled area covering 30.5ha. This small city was founded in 241BC and existed into the Medieval period, until around 700AD. It likely had a population numbering 3,000.

Using GPR antenna positioned on a trailer behind a quadbike and transmitting to satellite, echo-readings were taken every 6.5cm to produce 28billion data points enabling the entire city to be mapped in fine detail. Ground radar has been around since the 1910s yet more effective software and higher-resolution equipment has enabled significant advancement in this field technique.

“It’s impressive to see a whole Roman city buried deep underground,” says Martin Millet, Professor of Classical Archaeology at Cambridge, one of the study’s co-authors. “Only a tiny number of such cities are fully mapped like this, such as Pompeii and Ostia”.

“GPR enables us to map whole large-scale sites remarkably quickly, this took one person 3-4months in the field,” explains Millett. “It provides a very high level of detail and really does change how we study and understand Roman towns”

“We still have much to learn about Roman urban life and this technology should open up unprecedented opportunities for decades to come,” adds Millett. “It’s the future for archaeology”.

He suggests GPR can be upscaled to study ancient cities such as Cyrene in Libya and Nicopolis in Greece that cannot be excavated because they are too large or buried beneath modern buildings.

Fieldwork at Falerii Novi revealed both a higher level of architectural sophistication and less-standardised town planning than previously known for small Roman cities.

In one district known as Insula (Block) L, a very large rectangular building connects a network of waterpipes leading to an aqueduct. The authors conclude the structure was not a water cistern but an open-air natatio (pool) part of a bathing complex. Mapping showed water supply pipes ran throughout the city but underground and not alongside the streets as might be expected.

Further mapping also revealed two very large unknown structures never seen before in a Roman settlement close to the city walls. To the east of the North gate they found an enclosure defined on three sides by a substantial porticus duplex – a covered passageway with a central row of columns, 90metres in length. Within this complex is a pair of structures with a central niche facing each other.

“It was likely a public monument of some kind but does not resemble anything we’ve seen in other cities,” states Millett. He said it is impossible to say for certain it was a structure of worship as pretty much all Roman public monuments had some religious dimension.