The incredible Mer de Glace in Chamonix

The "Mer de Glace" has had this name since the 18th century, due to the numerous crevasses that look like frozen breakers. Arriving from the Col du Midi, this glacier descends towards the valley and meets the Glacier du Géant before merging further down into the Glacier du Tacul. Its main basin, upstream, is known as the Vallée Blanche. Its distinctive appearance is due to the small waves that are visible to the naked eye, iridescent with darker hues. The Mer de Glace gives the impression of being zebra-striped, alternating between white and darker bands, known as the Forbes stripes.

It is thought to have originated during the last ice age, when the ice cap covering the Alps melted. The Mer de Glace is therefore thought to have originated around 11,700 BC.

In the 17th century, this waterway was a threat to the surrounding dwellings, but today the Mer de Glace continues to shrink. In 2019, almost 10 metres of ice melted, reducing the thickness of this expanse. This is a glacial ablation zone, since the melting of the ice in summer is greater than the accumulation of snow in winter. In reality, the ice comes from higher up, in an area located at an altitude of over 3,000 metres.

From the Aiguille du Midi, you can ski to the Mer de Glace. All you have to do is follow a guide and the off-piste itinerary, to cross the Vallée Blanche and finish your slide on the Mer de Glace.

But if you're not a fan of this winter sport, don't panic! The Mer de Glace is big enough for everyone. From Chamonix, head to the station to catch the famous Montenvers train. Red in colour, it's easy to spot the platform and board one of the old-fashioned carriages.

The Montenvers Train runs on a railway that dates back to the last century, and was the first to cross this valley. Its purpose was to show these places to the tourists who were already flocking to Chamonix at the time. The Montenvers train first ran in 1908.

Departing from Chamonix, this little red train will take you to the heights, up to an altitude of 1,913 metres. The arrival station is perched on a rocky ridge, offering a breathtaking view of the Mer de Glace. You can also enjoy a hot meal up there, while taking in some wonderful views. There is also a museum dedicated to alpine fauna and an exhibition of mountain crystals nearby. Finally, if you want to spend a night on these heights, the Montenvers refuge offers magnificent sunsets and sunrises in the heart of the mountains.

The Glaciorium is located on the Montenvers Mer de Glace site and is only open in summer, from June to September. Created in 2012, the Glaciorium is an interpretation centre dedicated to answering visitors' questions about the Mer de Glace. How long has it been there? What is a glacier? Can there be life? How thick is it? These are just some of the questions that will be answered in the Glaciorium. For the most inquisitive of children, there's no doubt that this little visit will delight them and perhaps inspire them to take a greater interest in the environment.

The centre is also designed to answer questions about the climate. You might even find it easier to grasp the meaning of the term "global warming", or to understand the future of this glacier.

If you want to take a walk on the Mer de Glace, as soon as the train arrives, you can take a cable car. Then all you have to do is take a small path and descend more than 400 steps. After these few efforts, you'll be able to enjoy the Mer de Glace and appreciate just how vast it is.

A little further down is the Grotte de Glace, a unique place to discover with the family or on your own. Whether you're passionate about winter or the beauty of Mother Nature, you'll be able to feast your eyes on this corridor made entirely of ice!