The Cumana is the overlooked railway that takes you to the Phlegraean Fields. Pozzuoli, Baia, the underwater archaeological park — all reachable for €1.30–2.20.
Plan your trip →Departs from Montesanto station (reachable via Metro Line 2 or funicular). Runs west along the coast to Torregaveta. Key stops: Pozzuoli (Solfatara, Flavian Amphitheatre), Baia (Roman ruins, underwater park), Fusaro (Casina Vanvitelliana on the lake).
€1.30–2.20 depending on distance. EAV system (same as Circumvesuviana). Buy at Montesanto station.
Pozzuoli Solfatara: walk on a volcanic crater that hisses sulfur. Rione Terra: underground Roman city beneath modern Pozzuoli. Baia: submerged Roman villas viewable by glass-bottom boat (€12) or snorkeling (€30). Anfiteatro Flavio (Pozzuoli): third-largest Roman amphitheatre, intact underground passages, almost no tourists. All of this is 20–40 min from Naples for under €3.