
Already famous in Roman times, and quoted by Dante in his "Divine Comedy"...having a bath in one of their natural thermal springs is, perhaps, what you would never miss from Viterbo. As they are in surrounding open-air countryside areas, you can use them all year, every time of the day (for free, of course). Water reachs temperatures of 55º C, so the experience gets more amazing in freezing days (and nights).
The most famous ones are called Bulicame (2 km from Viterbo, on the road that leads to Tuscania). On the other hand there are also some springs run as spas centres (Terme dei Papi and Pianeta Benessere)
Main railway stations are Porta Fiorentina and Porta Romana. Both are quite close to the center. From Rome: trains [1] almost every hour, mostly departing from Roma Ostiense station (go and return for 10 €). The trip takes about 2 hours.
Take the motorway A1 (from Rome follow the signs towards Firenze, not to Viterbo!) and get out at exit Orte. Then take the S204 towards Viterbo (about 3 € tolls from Rome). It´s not really comfortable to drive inside the historical centre, as all the streets are quite narrow and "one way". You´d better park your car out of the town walls.