Grenoble Bastille: The Bubbles and the Mountain Troops' Fort

Required Activities

• Walk up from Saint-Laurent on General Haxo's staircase of 380 steps, broken every six steps by a landing with its own flight running off sideways to the parapet, and follow the 500 m curtain across the middle of the hill that ties the two arms of the fortification together — about 260 m of climbing to the fort

• Ride the bubbles the 700 m and 266 m of rise over the Isère, three to four minutes each way, and notice why they are spheres: the engineer Denis Creissels made them round so that everyone could see out, because in the old 21-seat boxes the tall men took the windows and the children in the middle saw nothing. Look down from halfway and picture the crowd on the quays on 18 September 1976, the day the new lift derailed on its inauguration and thirty-six people hung a hundred metres up for five hours

• Go into the Musée des Troupes de Montagne in the fort's casemates, free to enter, and follow its 130 years of alpine soldiering from the first battalions to the high-mountain group — the reconstructed First World War trench is the piece to stand in, and the audioguide is 2 euro

• Above the fort, find the battery caves cut into the mont Jalla cliff in 1844 and linked to each other and to the drawbridge by a tunnel, so the garrison could put fire into an attacker's back — and note that the local name, grottes de Mandrin, cannot be right: the Dauphiné smuggler died ninety years before they were dug