A section of the medieval fortress wall and a stone tower have been reconstructed at the southern edge of the Old Town and opened as a small open-air museum. The walls follow the natural cliffs that drop down to the sea; the tower contains a small display on the town's military and trading history, and the rooftop platform gives the best harbourside view in Sozopol.
Combined ticket with the Archaeological Museum is good value. The opening hours are seasonal — daily in summer, weekends only in winter.