For centuries, the fields along the Danube in Lower Austria looked like an ordinary rural plain, until geophysical instruments revealed beneath them a clear grid of streets and a huge oval arena. Researchers from the University of Innsbruck and partner organizations have discovered here the remains of a previously unknown Roman city with an area of 25–30 hectares, built according to a single plan and equipped with an amphitheatre for roughly eight thousand spectators.
The settlement arose around the year 80 AD in the area of present-day Sankt Pantaleon-Erla, not far from a small garrison of five hundred men. The city may have borne the name Claudivium, known only from ancient maps. The regular layout, wide streets and a monumental entertainment structure comparable in size to the amphitheatre at Carnuntum point to the considerable status of the settlement on the Danube frontier of the province of Noricum.
Particularly noteworthy is that life here came to an end around the year 180 — abruptly, but without traces of fires or destruction. Archaeologists speak of a planned, organized withdrawal of the population. During the century of its existence, the city managed to become a "time capsule": the short period of habitation makes it possible to trace everyday life on the Roman periphery clearly, from trade across the Danube to the cultural practices associated with the amphitheatre.
The discovery calls into question the familiar notion of Roman frontier settlements as modest military posts. Even next to a small fortress, a full-fledged urban structure designed for spectacles and trade could grow up. It is a reminder of how the empire could rapidly create infrastructure and then just as rapidly wind it down when strategic priorities changed.
Today the fields again belong to farmers, but beneath them an intact picture of the Roman presence is preserved. The geophysical methods used by the team make it possible to study the site without large-scale excavations, preserving it for future generations of researchers. Such finds show how much is still hidden beneath the familiar landscape of Europe.
Every new fragment of the Roman mosaic on the Danube forces us to rethink not only the maps of the ancient world, but also our own attitude toward what we consider "empty" space around us.
