Seuthopolis (Ancient Greek: Σευθόπολις) was an ancient hellenistic-type city founded by the Thracian king Seuthes III, and the capital of the Odrysian kingdom. The city was founded sometime from 325 BC to 315 BC. It was a small city, built on the site of an earlier settlement, and its ruins are now located at the bottom of the Koprinka Reservoir near Kazanlak, Stara Zagora Province, in central Bulgaria.