While the Tour du Mont Blanc is demanding, it’s not a particularly difficult hike. It’s just long, with lots of altitude gain and loss, and always scenic. On my recent trek around the mountain with three friends, it seemed each of us had a weak spot: knees, toes, or lungs. For some, the challenge was the uphill part, and for others (with weak knees), it was going downhill. We just took it easy, with lots of little breaks.