Gaeta to Siderno trains might be a good value for money solution: travelling in Italy by train is often rather cheap and faster than taking a bus indeed Trains leave from Napoli Centrale, Formia-Gaeta and arrive at Villa S. Giovanni, Siderno every 60 minutes on average. If travelling with Trenitalia, you need to know the Gaeta to Siderno train schedule: the first train leaves at 15:55, while the last ride is at 23:53. A Gaeta to Siderno train cost about 56.4 €. But how long is the train ride from Gaeta to Siderno? Your journey takes about 6 hours on average. Trenitalia offers 2 direct trains between these two cities.