Forte Zaccarana or Tonale is the highest fort, at 2,116 metres above sea level, and the most avant-garde fort in the Tonale area during the Great War. It was built in the early 1900s using the most modern criteria for the construction of armed fortresses. The fort guaranteed full control of all the surrounding valleys. The building can be reached on foot from Vermiglio by walking about 7 km along the old military road or from the path that starts from the Ospizio di San Bartolomeo, just above Passo Tonale. It was made safe in 2009 and the interior can be visited in part. From the fort you can enjoy a panoramic view of the entire upper Val di Sole.
