In Bagno Vignoni you cannot miss a visit to the Parco dei Mulini. A place you do not expect, in an evocative and natural environment; a journey made of history and curiosity.
The establishment of an important milling center in Bagno Vignoni, was basically due to three factors: the presence of the hot spring that guaranteed an abundant and perennial flow of water. An availability that is all the more important in Val d’Orcia, a land that has always had a vocation for cereal cultivation but is also characterized, due to the prevalence of clay substrates with low permeability and low-hill morphology, by a scarcity of springs; to the nature of the place by taking advantage of the substantial difference in height between the spring and the Orcia River, as many as four mills were built, placed in sequence along the limestone cliff; to the strategic position, due to its proximity to the Via Francigena, later the Roman Road, which lapped the town of Bagno Vignoni. The important thoroughfare crossed the Orcia River on a one-arch bridge, attributed to Baldassarre Peruzzi, the abutments of which still remain after collapsing in the early 1900s.
The technical and morphological singularities
The Mills of Bagno Vignoni are distinguished by two basic aspects: by the use of thermal water, captured by a channeling system directly from the spring basin; and by the largely hypogeal morphology, with rooms dug into the travertine cliff formed by the carbonate deposits of thermal water. The exploitation of the thermal spring, with its constant flow rate, allowed milling even in summer (when most mills were inoperative due to low river flow), but obliged to work in humid and hot environments (the water temperature at the spring was about 50°), and to have to constantly remove, before it hardened, calcareous deposits (the so-called tartar).
The decision to build hypogeal environments is in some ways an ingenious solution; given the steepness of the limestone cliff, the construction of traditional structures with above-ground volumes would have required considerable leveling and earthworks, and would in fact have been impractical. Here, on the other hand, everything is done “in the negative”: not only the mills, but also the gorells and conduits, the storage tanks, the ancillary rooms, down to the access roads themselves, carved into the half-slope of the slopes.
A complex system
The importance assumed by the mills is attested by thehistorical iconography of Bagno Vignoni: many images are captured right from the valley and put in the foreground, describing them minutely, the mills, the gorelli system, the storage tanks, and the tower that solitary stood guard over the whole system.
The four mills, from top to bottom, are:
- The disopra mill (or cape mill)
- The hole mill
- The Half Mill
- The foot mill
The first two, arranged along the limestone cliff, are totally hypogeal. In contrast, the middle mill, set at the foot of the cliff and the foot mill, located at the end of a canal that runs along the footpath, have structures that are partly above ground (the millstone rooms) and partly underground (the wheel rooms, known as carcerai). The milling technique, common throughout southern Europe, is that of the horizontal wheel mill, locally called retrecine: a relatively simple technology, with the driving wheels connected directly to the millstones via a vertical shaft and driven by a high-pressure water jet generated by a storage tank located at a higher level.