Mentana to Niscemi 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 Monterotondo-Mentana and arrive at Niscemi every about 6 hours on average. If travelling with Trenitalia, you need to know the Mentana to Niscemi train schedule: the first train leaves at 06:02, while the last ride is at 20:32. A Mentana to Niscemi train cost about 76.75 €. But how long is the train ride from Mentana to Niscemi? Your journey takes about 18 hours on average.