Fenestrelle Fortress

Built from 1728 to close the Chisone valley against France, Fenestrelle is not one fort but a chain of three linked forts and redoubts running up the mountainside over about six hundred and thirty metres of height difference and three kilometres of length, the largest fortification in Europe by area. A covered staircase of around four thousand steps runs the whole way inside the walls, protected from fire and weather, and it was climbed by garrison troops carrying supplies. It never saw a serious siege. Abandoned in the twentieth century and heavily overgrown, it has been cleared and restored by volunteers since 1990.

What you actually see

• The covered staircase - about four thousand steps inside the walls.
• The three linked forts - a chain climbing 630 metres of mountainside.
• The scale - the largest fortification by area in Europe.
• The volunteer restoration - a ruin cleared and rebuilt since 1990.

When to go

May to October; snow closes the upper works in winter. Tours are graded by length, from short walks to a full seven-hour climb of the whole structure.

Honest expectations

The full route is a serious hike with thousands of steps and takes most of a day. Shorter tours cover only the lowest fort. Guided visits are compulsory.

Nearby

The Chisone valley runs west; Turin lies east.