small entrance of the roman city of diocletianopolis, town of hisarya, bulgaria

ancient archeological archeology architecture brick bulgaria byzantine city destinations diocletianopolis diokletian diokletianopolis entrance europe fortification fortress gora hisar hisaria hisarya hissar hissaria hissarya historical landmark mineral mountain outdoor park plovdiv region remains resort roman ruins sights sightseeing small spa sredna stone structure the thrace tourism town vacation wall water