"You depart from the Crozat parking lot above Bionnassay in the valley and soon enter a dense coniferous forest that guides you up through zigzag paths. Then the landscape opens up to mountain meadows before you begin the climb. With every hundred meters you ascend, you are surprised by new views. The horizon broadens more and more until you have a superwide view over the valley you came from and the mountains you are heading to – especially the Fiz mountain range and the Aravis chain.
In the distance, the impressive Bionnassay glacier awaits. In some places, you walk surprisingly close to it. You can see where the ice used to be and how quickly the terrain is changing: rocks breaking free, lines in the stone. I even saw chunks of ice breaking off during my hike. It is extremely painful to see how quickly the glacier is retreating.
What is special about this route is that you briefly cross the path of the famous Tour du Mont Blanc. It can be very busy there, but you take a small branch, leading you back into quieter terrain. The final stage becomes more adventurous with steeper passages, rock sections, and a few cables and metal stairs that keep the terrain varied without making it too technical. After about three hours, you reach the Nid d’Aigle at 2,372 meters, with a spacious refuge where you can have something to drink or even spend the night. By the way, work is currently being done on a new tram line that goes all the way to the hut, an odd sight in this mountain landscape. But you can also do it the old-school way on foot."

Practical: 6 hours (same route back and forth). Starting point: Crozat parking to Nid d’Aigle.