Seuthopolis, in the Tundza River valley, near the modern town of Kazanluk, was almost completely excavated in 1948 - 1954 prior to the building of a dam, which then flooded the settlement remains.

Seuthopolis 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 B.C. to 315 B.C. 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. Seuthopolis was the only significant town in Thrace not built by Greeks, though it was built on an Ancient Greek plan.

Seuthopolis was not a true polis, but rather the seat of Seuthes and his court. His palace had a dual role, functioning also as a sanctuary of the Cabeiri, the gods of Samothrace. Most of the space within the city was occupied not by homes but by official structures, the majority of the people living outside the city. It had Thracian and Greek populace. In 281 BC it was sacked by Celts.

The dual role of Seuthes' palace (royal court and sanctuary) indicates that Seuthes was a priest–king: the high priest of the Cabeiri among the Odrysian Thracians. A hearth altar stood in the center of the Cabeiri sanctuary, the Cabeiri being associated with fire and metallurgy and with the smith-god Hephaestus.

The cemetery of Seuthopolis included a number of brick tholos tombs, some covered by tumuli, in which the upper-class were interred, sometimes along with their horses. The less affluent were cremated, with modest grave goods laid alongside.

The ruins of the city were discovered and excavated in 1948 by Bulgarian archeologists during the construction of the Georgi Dimitrov (later renamed Koprinka) Reservoir. However, it was decided to continue with the construction and flood the dam, leaving Seuthopolis at its bottom.

In 2005, Bulgarian architect Zheko Tilev proposed a project to uncover, preserve and reconstruct the city of Seuthopolis (the best preserved Thracian city in Bulgaria) by means of a dam wall surrounding the ruins in the middle of the dam, enabling the site's designation as a UNESCO World Heritage Site and making it a tourist destination of world importance. Tourists would be transported to the site by boats. The round wall, 420 metres in diameter, would enable visitors to see the city from 20 metres above and would also feature "hanging gardens," glass lifts, a quay, restaurants, cafés, shops, ateliers, etc. It would be illuminated at night. See

"SEUTHOPOLISTHRACE" by Megistias - Own work data fromThe City in the Greek and Roman World by E. J. Owens, ISBN-10: 0415082242, 1992, page 77, figure 22. Licensed under CC BY-SA 3.0 via Wikimedia Commons.

Also see:
Dimitrov Seuthopolis