Diocletianopolis (Thrace)

Its impressive remains include the enormous defensive walls which still stand close to their original height for the majority of their circuit.

Archaeological discoveries show that the site was inhabited from 6,000 years BC probably due to the many hot mineral springs nearby.

Later, a Thracian settlement developed there and in the 5th and 4th centuries BC it became a major market town trading with Greek cities on the northern Aegean as evidenced by the range of imported coins and pottery found.

After the fall of the Moesian Limes, the city declined until at the end of 6th to beginning of the 7th century it was destroyed during invasions of Slavs and Pannonian Avars.

An additional, double, wall (as also was done uniquely at other Roman cities in Thrace) was built outside the northern section only where there was no exterior valley, to counter increasing threats from the Goths.