We're planning to take the train from Rome to Florence. I'd love to see Orvieto; how hard would it be to take the train from Rome to Orvieto and then from Orvieto to Florence in one day? There are 10 of us, so another option we're exploring is getting a driver, but 10 people puts us in a mini-bus (I'm open to driver suggestions if anyone has any). Suggestions?
Lisa, I am a huge fan of travelling in Italy via train. The rail system is quick and reliable, and the connections from Rome and Florence are excellent. Plus you avoid the horrid in/out traffic of cities.
It is absolutely viable to do a day stop in Orvieto especially if you are willing to start your day early. There are regular intercity trains from Roma Termini to Orvieto which should take just over an hour and cost around 10EUR.
Once you arrive at the Funicolare di Orvieto (Orvieto Rail Station) you can walk (take a bus) to the nearby funicular that takes visitors up the hill, to the old town. Alternatively, you can get a taxi at the station... although I like the funicular :)
Remember also to check out the town's tourist card which gives discounted access to museum etc. It Should be on sale at the train station, look for Carta Orvieto (I think).
When you decide that you have had enough of sightseeing, just pop back down on the funicular, to the train station and catch another regular intercity to Florence (Firenze) which should take about 90mins and cost around 20EUR.
The rail website for Trenitalia has an English option http://www.trenitalia.com/cms/v/index.jsp?vgnextoid=4ddd1a035296f310VgnVCM1000005817f90aRCRD&gclid=CLelpZarpb8CFeyWtAodcB8AlA which will make it easy for you to check prices and times as well as buy/print tickets. There may be discounts for groups and also for advanced booking, though make sure to confirm your ticket is either time assigned OR flexible for any train time during a certain day. One thing to note is that the search will only work with the cities' Italian names so search for Stazione Roma Termini (Rome Main Station), Orvieto (unchanged) and Firenze Tutte Le Stazioni (Florence all stations, albeit you will likely use Stazione Firenze Santa Maria Novella).
Enjoy stunning Da Gianni... and just in case you might enjoy the read, here is a piece on my blog that includes the town as my top choices in Umbria http://www.aforkinlondon.com/post/73207590396/umbria
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