Terme di Petriolo (Monticiano)

Terme di Petriolo lies along the Farma River at the border between Monticiano (Siena province) and Civitella Paganico (Grosseto province) in Tuscany. Etruscan and Roman archaeological finds have been recovered at the site, and the springs were mentioned by Cicero and by Martial in an epigram. In the early 1400s a fortified stone thermal complex was built on the river's northern bank, drawing visitors from the Medici and Gonzaga families and Pope Pius II. The water flows at 43°C and contains hydrogen sulphide (21 mg/L), free carbon dioxide, calcium, fluorine, and chloride, sulphate, and bicarbonate ions, classified as sulphidic, saline-sulphate-bicarbonate-alkaline-earth, hyperthermal water. Petriolo was entered into Italy's official mineral water registry in 1907. Today it offers both free public bathing areas and equipped thermal facilities with associated hotels.