A small town not far from the slopes of Mount Amiata, famous for millennia for its sulphur waters, which were used by the Etruscans, and for the white calcareous deposits that form the small, spectacular hot waterfalls (48 °C – 118 °F) of the Fosso Bianco. Unlike the wellbeing and spa treatment centre, access to this area is free of charge.

Address: Terme San Filippo – Via San Filippo, 23
Il Fosso Bianco – Via San Filippo, 22
GPS: 42.92953, 11.70199
Phone: 0577 872982
www.termesanfilippo.it

This tiny ancient stone village has one unique and unforgettable characteristic: at its centre is Piazza delle Sorgenti, an ancient pool measuring 49×29 metres (not for bathing) where the spar waters are collected, gushing out at a temperature of 52 °C (125 °F) and shrouding the village in evocative steam during the cold months.

An 11th-century fortress transformed into a residential villa in the Renaissance, the castle – now a 5-star resort – is located on a hill overlooking the greenery of the Val d’Orcia, between Sant’Antimo and Montalcino. The indoor and outdoor swimming pools (and the bathrooms of some of the rooms) use water from a nearby thermal spring originating on Mount Amiata.

Address: Castello di Velona Resort Thermal SPA & Winery – Località La Velona, Montalcino (Siena)
GPS: 43.768268, 11.255412
Phone: 0577 839002
www.castellodivelona.it

The spectacular Grotta Giusti, on the outskirts of Montecatini, is a natural cave that winds its way among stalactites and stalagmites to a stretch of crystal clear water, the temperatures of which vary from 27°C to 34°C (from 80 °F to 93 °F). Above all mud therapy and balneotherapy are practised there in baths enriched with ozone to stimulate the metabolism of the blood vessels.

Address: Via Grotta Giusti, 1411 – Monsummano Terme (Pistoia)
GPS: 43.86556, 10.82927
Phone: 0572 90771
www.grottagiustispa.com

Classified among the “Most Beautiful Towns of Italy”, San Casciano stands on a hill immersed in the Siena countryside. The Bagno Grande and the Bagno Bossolo are ancient washtubs where it is possible to bathe freely, while there are indoor and outdoor baths, wellbeing treatments and a splendid resort at Fonteverde, sheltered by a magical garden with views of Mount Amiata.

Address: Fonteverde, Località Terme, 1 – San Casciano dei Bagni (Siena)
GPS: 42.87155, 11.87533
Phone: 0578 57241
www.fonteverdespa.com

Among the most beautiful free thermal baths in the world, the Cascate del Mulino are small natural pools supplied by small waterfalls that form a unique, unrepeatable environment. Next to them, the Terme di Saturnia complex has spring water pools, a wellbeing centre and a 5-star resort.

The thermal baths are sited on a natural spring in the Valley dell’Ombrone, along the course of the River Farma. The waters, rich in salts, gush out at a temperature of 43 °C (109 °F) and are traditionally used to treat various pathologies of the respiratory tracts.