Monterotondo to Trieste 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 Trieste Centrale every 60 minutes on average. If travelling with Trenitalia, you need to know the Monterotondo to Trieste train schedule: the first train leaves at 06:02, while the last ride is at 22:29. A Monterotondo to Trieste train cost about 60.1 €. But how long is the train ride from Monterotondo to Trieste? Your journey takes about 8 hours on average.