Stara Zagora was once Augusta Traiana, a significant Roman city founded by Emperor Trajan in the early 2nd century CE. It lay on the main road through Thrace and was large enough to have its own forum, temples, baths, and city walls. Unlike many ancient sites that are carefully fenced and ticketed, the Roman remains here are scattered informally through the modern city centre — fragments of forum pavement visible beneath glass in a pedestrian walkway, sections of the ancient street grid overlapping the modern one, and exposed archaeological layers in a few open excavation sites.
The Stara Zagora Regional Historical Museum collects the portable finds from the Augusta Traiana excavations, including mosaics, inscriptions, bronze objects, and architectural elements. The museum is the best place to get a coherent picture of the Roman city; the in-situ remains visible around the centre are atmospheric but fragmentary. Combined with the Neolithic Dwellings Museum nearby, the two sites make a compelling case for the extraordinary depth of human habitation in this part of the Thracian plain.