In ancient times the road connecting the Roman town Oescus with Serdica passed by. The place is still a crossroads of all the roads, connecting the Danube Plain with Sofia and the Eastern parts of Bulgaria with the Western ones.

The ruins of the ancient fortress that controlled the access to the passes of Stara Planina mountain are situated on a steep rocky hill, overhanging the river. To the North of the fortress there was a settlement, which is now covered by the present-day town of Mezdra.

At the fortress remains from the Prehistory to the Late Antiquity were discovered. The foundations of the fortification wall lay on a layer dating from the Chalcolithic Age. On top of the Roman fortress a Byzantine hill-fort was built.

The excavations revealed remains from various periods - dwellings, streets, objects. The layers at “Kaleto” have saved the history of the town and the items discovered witness for the richness and the prosperity of the ancient settlement.