Climate extremes reveal hidden Roman engineering along Danube

Exceptionally low water levels on the Danube River have exposed parts of the foundations of the ancient Constantine Bridge, offering Bulgarian archaeologists a rare opportunity to document what they describe as one of the Roman Empire’s most remarkable engineering achievements.

A succession of record-breaking heatwaves across Europe this summer has triggered severe drought conditions in parts of the continent, significantly affecting major waterways including the Danube and the Rhine.

“For archaeologists, these moments are extremely valuable because nature briefly reveals an object that is hidden beneath the Danube for most of the time,” said Pavel Popov of the Regional Historical Museum in Pleven. “It gives us a rare opportunity to observe, document and study it in its real environment.”

The bridge, commissioned by Emperor Constantine I and inaugurated in A.D. 328, once linked the ancient city of Ulpia Oescus with Sucidava, located in what is now Romania. Stretching more than 2 km (1.2 miles), it is regarded as one of the longest bridges of antiquity, although it was short-lived.

Historians believe the structure was largely destroyed around A.D. 355, likely during periods of conflict along the Roman Empire’s Danube frontier, after only a few decades of use.

By Tamilla Hasanova