Bagni di San Michele alle Formiche

About Bagni di San Michele alle Formiche

The Bagni di San Michele alle Formiche are a small sulphur spring in the countryside around Pomarance, in the province of Pisa, along the road linking Larderello and Pomarance. The name comes from the nearby hermitage of San Michele alle Formiche, an ancient religious site in the hills of the Val di Cecina. Here the sulphurous water collects in a pool next to the remains of an early 20th-century spa building, now abandoned.

Let's be clear from the start: this isn't a place for hot soaks. According to the source we consulted the water is around 25 °C, so rather cool. It's a destination better suited to the warm season, or to people who want to see a piece of forgotten spa history, than to anyone looking for the steam and hot pools of Saturnia.

We have marked it "to be checked" because no official source clarifies whether bathing is allowed, and some accounts warn that in dry periods the pool, which is fed by a well, may have little water. The square pool with its pale blue painted walls and steps to sit on is still there, though. The old spa buildings are derelict: don't go inside, and look out for any fences or no-entry signs, which must always be respected.

The area is fascinating for lovers of unusual places: we're a few kilometres from Larderello, the heart of Italian geothermal energy, with its cooling towers, steam and dedicated museum. A day around here can combine industrial history, geothermal landscapes and small villages such as Pomarance and Montecerboli.

If you decide to go, bring closed shoes, water and a towel, and think of the visit as an exploration. If you find the pool in good condition and bathing is allowed, remember not to use soap and not to leave anything behind. Any up-to-date report is welcome through our Report a hot spring page.

Bear in mind that the area sees few visitors and your phone may not always have good coverage: tell someone where you're going and don't venture alone among the abandoned buildings. The charm of these forgotten places lies in the silence and the feeling of discovery, but safety comes first.