Do you have to pay for the Saturnia hot springs?

No, not if you're talking about the Cascate del Mulino : access to the natural pools is free and you don't need to book. However, the parking and on-site services may be paid; check the posted rates when you arrive, as they are not an entrance fee to the springs.

Not to be confused with the Parco Termale of Terme di Saturnia, which is a developed, paid facility: the day pass is currently listed at environ 42 € per person, with wellness kit and slippers included. Access to the Club, which is more comprehensive, is listed at about €100. Prices may change, so check them before you go if you want to choose this option.

At the waterfalls, bring water sandals: the limestone rocks are uneven and slippery. It's a natural site, not a spa with the same facilities; also bring a towel and water, and keep your belongings with you. The pools are outdoors, so crowds and comfort vary depending on the time and season.