In Upper Valsessera, in the Oasi Zegna nature park (Biella, Piemonte) it is still possible to visit the remains of mines that had been used since the Early Middle Ages.
Archeological digs revealed old mines dating from the 17th and 18th centuries.
The Opificio Argentera and Opificio Rondolere, both on the banks of the Sessera, provide evidence of the working of lead, silver and magnetite, a particularly sought after mineral.
The Rondolere site can be reached by a path that starts at Bocchetto Sessera.
