Capodichino International Airport, 7 km northeast of the city centre, links Napoli with most Italian and several European cities, as well as New York. The airport is served by bus lines and taxis (predetermined fares might apply, see here). Alibus stops to Stazione Centrale (railway station) and Piazza Municipio, near the main ferry port (molo Beverello). An Alibus ticket (5€) can be bought at the airport or on board (with no surcharge) and is valid for a single journey on Alibus and for all lines of the UNICOCAMPANIA consortium within the Napoli urban area. You must validate your ticket when using it for the first time. The ticket is valid for 90 minutes from the first validation. Yellow validation machines are not always obvious - you may have to look for them. Having an unvalidated ticket is the same as not having a ticket at all and will get you a fine.
Ferry lines connect Napoli with Sorrento, and there are daily ferries to Catania, Palermo, and Cagliari. Urban links from the ferry station include the Alibus line and the Municipio metro station.
The main railway station is Napoli Centrale. Different options are available. For example, travel times to Rome range from 2 hours with a regional train to 70 minutes with high-speed trains. Costs vary accordingly.
At Napoli Centrale, transfer options include the Circumvesuviana station with trains to Pompei and Sorrento, the Metro lines 1 (Garibaldi station) and 2 (Piazza Garibaldi station), as well as buses in front of the station.