Use the train that goes North from Naples (Napoli) and connects through Pompeii, Ercolano and keeps heading north to Baiae/ Pozzuoli (the Circumvesuviano)
I can’t answer but very much support the question. I’m thinking of a holiday in Sorrento and having visited other Roman sites would like a fresh location. I saw a TV documentary on Baia a year or two and thought it was fantastic. Comprehensive direction for public transport from Naples (itself easily reached from Sorrento) would be very much appreciated e.g get the x bus or train from y station.
Get quick answers from Baia Archeological Park staff and past visitors.