The Roman Baths of the Ancient town of Diocletianopolis (Municipality of Hisarya) – the pearl of the archaeological reserve and the newest attraction in Hisarya. The Roman town of Diocletianopolis (now Hisarya), founded by Emperor Diocletian in 293 AD, was the third largest town in the province of Thrace after Philippopolis (Plovdiv) and Beroe (Stara Zagora). The rich thermo-mineral deposit near the nowadays town of Hisarya has defined the healing and restorative nature of Diocletianopolis since ancient times. It was also the main reason for the town to develop and become the largest balneotherapy centre in the Eastern Balkan Roman provinces.