Water is a dominant element also in Sarteano, and it is possible to follow its evocative path running downstream to the valley, reliving two millennia of history. From the source, which is now used to fill the pools of the campsite, the water was once divided into two streams, at the point where the so-called "spartitoi" [splitters] were located: one of them skirted past the walls of the town and served to irrigate the vegetable gardens, the other irrigated the surrounding fields. Until 1857, the year in which the central square was completely re-laid with the demolition of the old parish church of San Martino [St. Martin] and the relocation of the central fountain, the water coming from the spartitoi ran into the "gora di piazza" [canal of the square]. This was blocked following the work. The water ran free, however, past the walls of the town until 1957, the year in which it was channelled under the road. Beyond the main square, where today the Locanda dei Tintori [Dyers' Inn] is located, there was once a first mill, in use until 1950. From there the water split into further streams: towards the washhouse, today the location of the Municipal Library, on towards Radicofani, and the other down towards the Val di Chiana. The course that descends towards the Astrone is dotted with little churches and, at one time, mills, as many as 18, of which today only the evocative ruins of two are visible. The little churches, as many as seven of them, were most likely built on pagan sites dedicated to the cult of water. Past the Porta di San Martino [Gate of St. Martin], and taking the road towards the cemetery, we encounter the first: "Chiesina della Concia" [the little church of Tanning] of which only the gable remains visible, continuing on lies the Chiesa di Santa Vittoria [Church of St. Victoria], deconsecrated and roofless, now used for shows, the Chiesa del Crocifisso [Church of the Crucifix], which is now a private residence, the shrine of the "Madonna dell'uccellino" [Our Lady of the little bird], the private chapel of the Borselli family, the shrine of "Madonna del Maldicapo" [Our Lady of the Headache], and the beautiful Chiesa delle Spiagge [Church of the Beaches], today private and not accessible, around which an imposing wall of travertine blocks, connected to one of the "vie cupe" [gloomy streets] that descend towards Chiusi, suggests a fortification from the Etruscan era. Also close to the cemetery, the large structure of the so-called "Gorone" [large canal] is a part of the large channel system that was still in use until the last century.

Going down beyond the ruins of the old mills, following the domineering flow of the falling water, one arrives at the remains of the Roman baths of Peschiera Giannini, whose former magnificence is testified by a 36-metre wall in opus reticulatum [reticulated brickwork] style. From there you can return to the town by following the atmospheric route of the two "vie cupe" of Etruscan origin, with their high overhanging walls carved from travertine. In the area of the Palazzina, the walls of the road are pockmarked with hollows: Etruscan tombs excavated in antiquity and now mostly filled, which mirror those excavated in 1997 by the Museo Archeologico [Archaeological Museum] and whose relics occupy room III of the museum.