Located in Chamonix, France, this 15km, 2000m D+ alpine round trip crosses Mont Blanc du Tacul, Mont Maudit, and the Mont-Blanc summit.

To accommodate varying alpine schedules, it starts and finishes at either the Aiguille du Midi ice tunnel (3,842m) or the adjacent Refuge des Cosmiques (3,613m), two equivalent points on the Col du Midi.