The Archaeological Museum is small but unusually rich for a town of Sozopol's size. The collection covers Apollonia Pontica, the Greek colony founded here around 610 BC, and runs through the Roman, Byzantine, and medieval periods. The standout is the painted Greek pottery — black-figure and red-figure amphorae, drinking cups, a few intact ritual vessels — most of it dredged up from the harbour or recovered from underwater grave sites.
The museum is on Han Krum Street, near the bishop's palace at the north end of the Old Town. Allow an hour. Entry is cheap; English captions are partial but the displays are largely self-explanatory.