The Fort du Télégraphe, or Fort Berwick, is located in the Maurienne valley on the road to the Col du Galibier between Valloire and Saint-Michel-de-Maurienne, at the Col du Télégraphe, dominating the valley of the Arc. The location at an altitude of previously accommodated a telegraph of the Chappe system using articulating arms to send messages between Lyon and Milan, and after 1809, Venice. The fort has two entrances with drawbridges to allow access to different levels of the fort, with inclined ramps to allow easy movement of artillery pieces. When completed in 1884 after four years of construction, the fort was manned by 170 men, firing four artillery pieces at the main fort and four more at detached batteries.