Being a circular route, the Tour of Mont Blanc could be walked in either a clockwise or an anti-clockwise direction, and started from any one of a number of places. By tradition it has begun in the Chamonix valley (the Vallée de l’Arve), but not in Chamonix itself, for in order to make the most of the splendid views afforded of Mont Blanc from the slopes of the Aiguilles Rouges chain, the route avoids the bed of the valley except to cross it at either end. Instead, by tradition the TMB begins about 7km downvalley from Chamonix, in Les Houches, and tackles the circuit in an anti-clockwise direction.

The Tour of Mont Blanc lasts between 9 and 13 days — depending upon your level of physical fitness - averaging 5 hours walk daily, between 800m and 1000m daily climb and crossing 3 countries: France, Italy and Switzerland.

The easiest way to reach the Mer de Glace glacier from Montenvers railway station is to take the gondola ski lift that descends from the platform down to the valley floor, a couple of hundred metres below. Yet Olivier, my guide from the Compaigne des Guides de Chamonix Mont Blanc, isn’t having any of that.