Below the village, the thermal water that overflows from the Piazza delle Sorgenti runs down through a series of cascades and channels before joining the Orcia river. The Parco dei Mulini — Park of the Mills — follows these channels through the valley, passing the ruins of several medieval mills and offering fine views back up to the village perched on its ridge above. The walk takes about thirty minutes at an unhurried pace.
The most dramatic section is immediately below the village, where the hot water drops in white cascades over dark volcanic rock. In winter especially, the steam and the silence and the view of the empty Val d'Orcia are extraordinary. Several pools along the route are warm enough for soaking your feet, and on cooler days the thermal water is noticeably warmer than the surrounding air. The park is free to enter and open at all times.