The Farma River flows through the green silence of the Merse Valley, nestled between the hills between Siena and Grosseto. Here, the Petriolo Thermal Baths are much more than a place: they are a natural panacea, a small miracle of nature and history that challenges the ephemeral nature of modern life.
Petriolo: where wellness comes from the heart of Tuscany
The waters of Petriolo have been known since Etruscan and Roman times, and their therapeutic value has been admired and exploited over the centuries. In the 15th century, under the protection of the Republic of Siena, the "Bagno Nobile" was built, with fortified walls and loggias, a structure designed to protect both the thermal spring and the economic and social revival that ensured the spa a place of honor. Once a favorite destination for lords, nobles, and travelers, Petriolo's fame has endured periods of splendor and decline. Today, amidst ruins and memories, its natural springs continue to speak of the grandeur of its past.
A free spa experience, immersed in nature
Le terme libere di Petriolo sono la parte più autentica di questo luogo: vasche naturali che l’acqua calda, sulfurea (intorno ai 42-43 °C) e ricca di minerali—zolfo, calcare, magnesio—forma spontaneamente tra le rocce e i ciottoli del letto del fiume Farma.
Qui non c’è ingresso, né biglietto: basta camminare da un parcheggio lungo la strada, proseguire per un breve sentiero immerso nel bosco, raggiungere la riva e lasciarsi avvolgere dal calore rigenerante.
Le vasche naturali si susseguono, con temperature diverse: si può scegliere tra il calore intenso delle vasche superiori e zone più tiepide per lunghe immersioni. C’è il “calidarium” naturale, il “tepidarium”, e addirittura il “frigidarium” naturale rappresentato dal corso più freddo del fiume Farma. Il contrasto è parte del fascino.
Benefits for body, mind and skin
Therapeutic effects: the sulphurous and hyperthermal waters promote the treatment of joint, rheumatic and skin problems, and also contribute to muscle and nervous relaxation.
Psychophysical regeneration: being immersed in nature, far from noise and haste, with the pleasure of warm water on your skin and the sound of running water. It's an experience that also heals the soul.
Rigenerazione psicofisica: stare immersi nella natura, lontani dal rumore e dalla fretta, con il piacere dell’acqua calda sulla pelle e il suono dell’acqua che scorre. È un’esperienza che cura anche l’anima.
When to go and how to prepare
Recommended period: September to May is ideal: milder temperatures, fewer tourists. During high season, the free spas can be very busy.
Useful gear: water shoes, towel, something to eat and drink. Avoid silver jewelry (sulfur can tarnish it).
How to get there: From Siena or Grosseto by car; from Casa Olivo, about 30 minutes. There are also bus connections to nearby destinations, followed by a short walk. The area can be reached by following the main roads of the Sienese hills.
Petriolo today: a fragile beauty to be protected
Petriolo is a living testimony: nature, water, and history intertwine. But it's also a place that demands respect. Free spas lack large-scale infrastructure, management is often minimal, and their natural beauty must be preserved: no waste, no damage, respect for the natural rhythms of the water and the landscape.
If you're looking for an oasis of true relaxation, where the healing waters speak to the centuries and nature embraces the senses, the Petriolo Spa is a dream come true. A place to stop, breathe, and immerse yourself—in the warmth of the water and the distant silence—to return home feeling lighter inside.
