Archaeological site — Avantas, ~15km northwest of the city
The Castle of Potamos sits above the village of Avantas, one of a pair of medieval fortresses (the other is Avantas Castle) built to guard the approach to Traianoupolis from Bulgarian and other northern raids. Estimates for its construction vary — some sources point to the Genoese Gattilusi rulers in the 13th century, others to the Late Byzantine 14th century — but it clearly saw more than one building phase.
The site itself layers three distinct eras: Mycenaean and Classical-period remains underneath a Byzantine fortress, with the walls later inhabited into the 20th century before the region joined Greece in 1920. It's a quieter, more rugged alternative to Ancient Maroneia for anyone drawn to the region's less-visited ruins.