World War I Fortifications
Discover the First World War forts in the Adamello–Presanella mountains, between Lombardy and Trentino. Six fortifications lead you into the places of the White War, when the Tonale Pass marked the border between the Kingdom of Italy and the Austro‑Hungarian Empire. Fort Strino, Zaccarana, Mero, Pozzi Alti, Velon and Corno d’Aola, these military posts were built to control and defend a strategic territory under extreme conditions , frost, snow, ice and high altitude. Today, the forts can be visited and reached along trails and ancient military paths. Some also host exhibitions and events dedicated to the history of the Great War.
Fort Strino
Fort Strino stands along the Tonale state road, between the Pass and Vermiglio, just before the bridge over the Rio Strino. Built by the Austrians starting in 1860, it was intended to defend the southern border of the Austro‑Hungarian Empire. After the First World War it was gradually abandoned, before being restored in the 1990s. Today it is part of the museum network dedicated to the Great War and preserves artefacts and testimonies from the conflict, including the camouflage uniform of the Alpine ski troops. The fort can also be visited through guided tours.
Fort Zaccarana or Tonale
At 2,116 metres above sea level, Fort Zaccarana was the highest and one of the most modern forts in the Tonale defensive system. Built by the Austrians in the early 20th century using the most advanced criteria of the time, its strategic position provided control over the surrounding valleys. Today it can be reached on foot from Vermiglio, walking about 7 km along an old military road, or from just above the Tonale Pass, following the trail that starts at the San Bartolomeo Hospice. Secured in 2009, it can be visited partly inside and provides a wide panoramic view over Upper Val di Sole.
Fort Mero
Fort Mero was the last structure built in the Tonale fortified system, built between 1911 and 1913. Designed for close‑range defence and controlling the area between Fort Zaccarana and Fort Presanella, it had no cannons, but it was armed exclusively with machine guns. On some of its walls, you can still see traces of the paint used to camouflage the structure within the surrounding landscape. Just three years after its completion, the fort was destroyed by Italian artillery fire. Today it can be reached on foot from the San Bartolomeo Hospice, and a nearby rest area provides facilities for visitors.
Forte Pozzi Alti o Presanella
Fort Pozzi Alti, also known as Fort Presanella, was built between 1908 and 1912 in Val Vermiglio, on the opposite side from Fort Zaccarana. Heavily damaged during the early stages of the First World War, it was further demolished after the conflict to recover iron and other materials. In 2008, work began to secure the remaining ruins, funded by the Autonomous Province of Trento. Today, the fort can be reached on foot from Velon, a hamlet of Vermiglio, by walking about 8 km along the old military mule track.
Fort Velon
Fort Velon is a small Austro‑Hungarian fort located downstream from Fort Strino, which it was connected to by an armoured concrete staircase. Its function was to provide close‑range defence for the fort above while also controlling the valley floor. Today it cannot be visited, but its ruins are still visible along the Tonale state road, just after Vermiglio.
Forte Corno d'Aola
Fort Corno d’Aola was the only Italian fortification defending the border in this area. Built between 1900 and 1913 at an altitude of 1,964 metres above sea level, it stood on the slopes of Corno d’Aola, above Ponte di Legno. At the end of the Second World War, it was blown up by retreating German troops. Today, only a few ruins survive in the Valbione area, which can be reached from Ponte di Legno either by taking the ski lifts or the road.
