Taking the famous little rack railway from Chamonix for approx 20 minutes with great views looking down over the valley reaching the bottom of the Mer de Glace (1913m), France's largest glacier. Offering famous panoramic views of Les Drus and Les Grandes Jorasses. I would recommend visiting on a clear sunny day to take full advantage of these views, they really are something. I was amazed to see people actually snowboarding and skiing the glacier (Vallée Blanche), this is an off-piste ski route, 20km long with a vertical descent of 2700m.
Click on image to enlarge
Click on image to enlarge
Grotte de Glace - (Ice Cave) - Takes you into the heart of the glacier, firstly jump on the Gondola lift which takes you down halfway then from the arrival of the Gondola lift to the entrance to the cave there are more than 300 steps down. Tiring and "brrr" but fascinating.
The Glaciorium - New exhibition centre that explains in detail the creation and evolution of the glaciers over the centuries. Inside there is an interesting model which takes you through the change of the glaciers along with a short video.
The Galerie des Cristaux - (Crystals Gallery) - Exhibits an impressive collection of rocks from the Mont Blanc massif.
For more info: Montenvers - Mer de Glace