The first impression of this fort is truly striking as this incredible cascade of stone is one of the largest fortresses in Europe. It comprises a huge complex of forts and redoubts linked by a covered 4 000-step staircase which runs for 3km in length from the crest of the mountain with an incline of 635m. Started in 1728, construction lasted 120 years. Fenestrelle was dismantled for good in 1946 at the request of General de Gaulle.