Burgas Airport: The sensible budget route is the airport bus into Burgas, then a southbound bus from Burgas South Bus Station to Sozopol. Allow roughly 1.5–2 hours including the connection; the bus legs are inexpensive, generally a few Bulgarian lev each (check current fares and timetables in season). A pre-booked direct transfer is worthwhile for late arrivals, families or luggage: about 45–60 minutes to Sozopol. Do not accept an unpriced airport taxi ride.
Burgas Central Railway Station / Burgas South Bus Station: Burgas is the useful rail and long-distance-bus gateway. The railway station is beside the South Bus Station; take a direct Burgas–Sozopol bus, usually about 45–60 minutes. Summer brings frequent services, but do not assume the same frequency outside the beach season or late at night.