Crossing the Valdarno on foot allows you to immerse yourself in unique and fascinating nature that's dominated by the Balze. These are rock formations with prehistoric origins that owe their appearance to erosion. This area forms part of the Protected Natural Area of local interest. The Balze form unusual shapes in the landscape and create contrast with the green slopes and cultivated vineyards that stretch out at their feet. One of the most fascinating itineraries that allows you to admire them is the Sentiero dell’Acqua Zolfina, a ring route that's just over 7 km long, signposted CAI 51. It doesn't present any particular hiking difficulties.
The trek starts from the village of Castelfranco di Sopra, specifically from the Badia a Soffena, an attraction that's worth visiting either before or after the excursion.
Leaving the town, proceed along an asphalt road that gives the first glimpses of the countryside and the Balze. Following the Borro delle Fossate, you reach Botriolo where you leave the asphalted stretch and continue along a dirt road towards Riguzze.
The landscape changes quickly along the cultivated fields and vineyards, getting closer and closer to the area of greatest naturalistic interest.
At the Borro della Fornace, take the uphill detour that leads to the small perched hamlet of Piantravigne. Once at the top, the spectacle of the Balze opens before us in all its beauty: the yellowish colour of the earth characterizes them and contrasts with the green of the countryside; the linear geometry of the rows of vines seems to relax and softens the harshness of the rocky walls that rise above them.
From Piantravigne, take the road that was taken on the outward journey until you reach Borro della Fornace once again and continue along the path.
The itinerary partially leaves the countryside and gets closer to the wood as it approaches the source from which the route's name is taken: the Sorgente dell'Acqua Zolfina is a natural spring of sulphurous water, recognizable even from a distance due to its scent of sulphur.
After passing the source, you dip into the wood for a small stretch, leaving behind the view of the Balze and instead greeting the Mediterranean scrub. The forest ends when you approach the Sette Ponti provincial road, which is the last stretch of the itinerary and leads to Castelfranco di Sopra and the starting point.
For more information on the characteristics of the route, visit: caivaldarnosupreste.it