The thermal springs in Petriolo, on the river Farma between Siena and Grosseto, have been a pleasure destination for centuries.

Folgore da San Gimignano, a 13th-century comic-realist poet, mentions them in the first verse of one of his sonnets dedicated to the twelve months – “And in November Petriuolo, the baths”. The poem is included in a collection of his, dedicated to “plazer” (Provençal for “pleasure”), which lists a series of enjoyable social situations in rhyme, following a tradition appreciated by many medieval literature critics.