Derborence tunnels

Day suddenly changed to deep night

Disaster came twice: two landslides in 1714 and 1749 that crashed down into the Lizerne valley. Two years after an important earthquake which had weakened the mountain, rocks fell in the western region on 23 September 1714, causing the death of 15 people living there and 100 cattle as well as innumerable sheep, goats and pigs.

According to reports: “At the moment of the cataclysm, the air was suddenly darkened, to the point that the day was changed into a deep night. The dust that rose into the air spread so thick on the nearby pastures that the cattle had to be evacuated.”

The landslide destabilized part of the limestone wall leading to the summit, and nearly 35 years later, on 23 June 1749, this came down, an estimated total of 50 million cubic metres of rock spreading across 5km of the valley.

This time there were no deaths, because shepherds were warned by rocks falling in the days prior.

One result was the formation of Europe’s youngest natural lake, known today as the Lake of Derborence.

Lake of Derborence

Another result was that the rocks above Derborence became known as Les Diablerets (Devils Mountain). Some 1500m above the valley is the 40m-tall Quille du Diable (Tour de St-Martin) (“devil’s skittle”), which locals suggested demons used as a target for throwing giant stones, which often went tumbled down into the valley.

The Devil’s Skittle

They even claimed to have seen lights carried by devils during the 1714 rockfall, and reported a battle between the rival demons from Protestant Berne and the Vaud and those of the Roman Catholic Valais trying to hold back the stones and causing the sounds of their clashes to come from inside the mountain.

Today the Quille de Diable, at 2908m, can be reached from the Scex Rouge (Red Rock) and its two aerial tramways. Nearby is a building created by the renowned Swiss architect Mario Botta. Since October 2014 it has boasted the first suspension bridge connecting two mountain peaks, a 107m walk over the gorge, as well as the world’s highest toboggan run at Glacier 3000.

Glacier 3000’s map of its attractions. The Bille du Diable is at the left, the Botta restaurant at the right.
This is known as the Easy Summit. The walkway linking two peaks over a gorge is in the background.

From Deborence way below in the valley, the challenging 4 to 7-hour hikes (the estimates vary) can take you the 8.5/15.09km up 1000/1922m to the Quille de Diable and from there to the Scex Rouge (between July and September), though the authorities warn off people who suffer from vertigo. It is steep and rocky, they warn.

Its dangers gained some notoriety with the publication in 1934 of Derborence by the Swiss novelist Charles-Ferdinand Ramuz (1878-1947) dramatizing the 1714 events. A translation was published in English in 1947 as When the Mountain Fell. The subsequent film by Francis Reusser won a French César award as the best French-language film in 1986.

But it is the unusual natural history and biodiversity of the valley that brings visitors to Derborence today. It is still not inhabited year round and public transport does not run from the Mediterranean-climate lower regions of Conthey and Aven or Sion until late in June.

Glacier 3000, architecture by Mario Botta, rebuilt after September 2022 fire

The local website proclaims (in French): “Stacked over a thousand metres, gigantic sheets of stone tell the fantastic story of the formation of the Alps. Ancient coral reefs more than 150 million years old, fossils of marine animals from a tropical climate, ancient volcanoes active nearly 35 million years ago, [the] folds of rocks, formed in the depths of the earth’s crust, were gradually lifted and folded 25 million years ago. These underwater rocks today rise up to more than 3000m above sea level. All these elements are still preserved and legible in the landscape.”

Its 18th-century disastrous history ensured that animals could survive in these wilds largely undisturbed. As a result, from the Alpine Salamander /Salamandra atra (found only here in the Valais, which is otherwise too dry) to the golden eagle, the ibex, deer and lynx, even re-introduced bearded vultures, can be all seen by alert watchers. Swiss biologists consider it a paradise for birds.

Sweet cicely

But the valley’s flowers and plants flourish in a microclimate that mixes the drier continental environment of the mountainous Valais with the humid winds typical of Lake Geneva. Botanists have found the very rare Myrrhis odorata (sweet cicely) and Lilium bulbiferum (orange lily or tiger lily) in Derborence, Pro Natura Valais records.

Tiger lily

Derborence is even better known to contemporary Swiss for its largely unchanged virgin pine forest known as l’Ecorcha (maybe a reference to the scorching effects of the 1749 landslide) on the steep slopes above the lake. Some trees are 450 years old, rising up to 44m in height. The forest is only some 25 hectares in size but is one of the last three natural forests of Switzerland with spruce, pine, larch, scots pine, beech and willows.

Refuge du Lac

Switzerland’s Pro Natura took control of the natural forest and adjoining alpine meadows from 1959 on, giving it management of 250ha, and no changes can be made without federal permission. Strict rules ban the collection of plants and restrict use of the area.

Nature sensitive barriers to walkers on lake paths

According to a 1961 decree, “In this territory, it is forbidden to leave the trail, to collect the wood, even dry or recumbent, to collect natural waste material, to let dogs roam, to gather plants, flowers, berries and mushrooms, to capture or kill any animal whatsoever, to bivouac / camp, to make fire, to abandon any waste, to bathe in the lake, to use drones and, except for border licensees, to enter with motor vehicles.”

Because of its harsh winters, spring comes late to Derborence. So even in June species such as orchids of various varieties can be seen here in the woods and fields much after they have reached the end of their lives elsewhere.

But with hardly anyone except adventurous young people or elderly e-cyclists brave enough to push or drive their way 20km into the valley through its many rock tunnels, you can often enjoy sunny days with hardly anyone around in June, except at the two excellent restaurant-hotels at the end of the road: the Chalet de Godet and the Refuge du Lac.

Chalet du Godet

But even after the postal buses start running, it is still worth your time for a day’s outing. And you might spot some rare fauna or flora, as well as wonder at what wild nature has wrought in one of the most developed nations of the world.

And you can follow the postbus journey on YouTube:


Fresh Snow at Glacier 3000, Switzerland, Just in Time for Re-Opening of Glacier 3000 Cable Car (and the story behind it). 9 August 2023 (LINK)

Restaurant Glacier 3000 ready to open in spring 2024, only 1 year after devastating fire. 19 September 2023 (LINK, French)