The fortress features a 'covered staircase' (Scala Coperta) that is the longest of its kind in the world, spanning over 2 kilometers.
The complex was never captured by enemy forces during its active military service.
The masonry tunnel housing the stairs was designed to withstand winter avalanches and heavy snow loads.
The San Carlo fort contains a monumental church built directly into the rock face.
During the post-Risorgimento period, the fortress held Bourbon soldiers from the Two Sicilies as prisoners.
The defensive walls are built to follow the natural, rugged topography of the mountain ridge.
The fortress remains a site of ongoing archaeological and structural restoration efforts managed by a dedicated non-profit association.
It is often referred to as the 'Great Wall of the Alps' due to its scale and continuous stone fortifications.
Fenestrelle Fortress is the largest alpine fortification in Europe, sprawling across 1.3 million square meters in the Chisone Valley. Commissioned by Victor Amadeus II of Savoy in 1727, the structure was built over 122 years to protect the border against France. It consists of three separate forts—San Carlo, Tre Denti, and Delle Valli—connected by a massive covered staircase. This 'La Scala Coperta' contains 4,000 steps protected by an arched masonry tunnel, allowing troops to move safely between levels. The site served as a military prison throughout the 19th century, most notably during the Risorgimento. Its elevation ranges from 1,100 to 1,800 meters above sea level. The fortress occupies a strategic position along the Piedmontese Alps, overlooking the road to Sestriere.
The view from the top of the San Carlo fort looking down the entire length of the zig-zagging defensive walls.
Wear sturdy hiking boots as the site involves significant vertical climbing on uneven stone terrain.
Carry a light jacket even in summer, as temperatures drop considerably inside the stone tunnels and at higher altitudes.
Bring a high-powered flashlight to explore darker, unlit sectors of the tunnel system.
Do not attempt to walk the entire 4,000-step staircase without assessing your physical fitness, as the return trip is just as demanding as the ascent.
Guided tours are mandatory for most areas; site access is limited or restricted during heavy winter snowfall.
Maintain silence in the chapel areas and adhere to all marked safety barriers, as many sections feature steep drops.
