Zinal Glacier in Winter: a Guide to the Sapphire Ice Caves
Deep in the heart of Switzerland’s Val d’Anniviers lies a winter wonderland straight out of a fantasy novel. If you are looking for a trek that goes from peaceful, snow-blanketed valleys to wild, high-alpine exploration, then the journey from Zinal to the frozen sapphire ice caves of the glacier is one of the ultimate Swiss adventures.
Clocking in at roughly 14 kilometers round-trip with about 450 meters of elevation gain, this trail offers some dramatic alpine scenery. Here is your guide to conquering this bucket-list winter trek.
Stage 1: Leaving Zinal Behind…
The adventure begins at the Zinal Holiday Village bus stop. Stepping onto the trail, you are immediately immersed in the wild beauty of this valley in winter. Pristine, deep blankets of snow cover the valley floor of Les Plats de la Lee, transforming the landscape into a silent, white wilderness.
As you walk, make sure to keep left of the groomed cross-country skiing tracks (piste de fond). The trail runs parallel to the frozen, rushing waters of the Navizence river. Take in the quiet stillness of the snow-dusted pine trees until you reach the wooden bridge that crosses the river.
Stage 2: Ice Climbers & a Hidden History
Once across the bridge, the environment turns increasingly dramatic. You are dwarfed by steep, towering mountain walls that block out the low winter sun, throwing parts of the canyon into deep, moody shadows.
In the dead of winter, massive waterfalls cascading down these cliffs freeze into vertical pillars of ice. You will frequently spot adventurous ice climbers anchored to these sheer, frozen walls. As you look up to the left on the way up, your eyes will immediately be drawn to the Besso (3,668m) - a beautiful, incredibly sharp, and jagged mountain peak that dominates the skyline.
As the trail begins to wind upward out of the lower forest, you will pass a small, snowed-in alpine shelter directly on the left side of the trail. This is the Le Vichiesso outdoor museum.
Long before Zinal became a world-renowned ski resort, the Val d’Anniviers relied heavily on traditional alpine farming and seasonal migration. At Le Vichiesso, you are standing next to a meticulously reconstructed tsigière (a traditional stone-and-wood alpine pasture chalet) and its historic cheese storeroom.
The Winter Peek
While the building’s interior is locked during the winter months, the un-enclosed side of the shelter remains open to the elements. As you walk past, you can peek right inside to see the massive, historic copper cauldron once used by early Swiss farmers to heat fresh milk over an open fire.
As the trail begins to wind upward out of the lower forest, you will pass a small, snowed-in alpine structure. This is the historic entrance to La Mine de Cuivre de la Lee (The Lee Copper Mine).
Ghosts of the Valley's Past
Long before Zinal became a world-renowned ski resort, the Val d’Anniviers was a hive of grueling industrial exploration. Miners discovered copper here in 1832, enduring treacherous alpine conditions to chisel over 500 m of tunnels straight into the mountain. Sadly, the ore concentration was too low to be profitable, and the mine was abandoned by 1903.
The Summer Twist
Though the site is closed and silent in winter, it transforms into Switzerland's only publicly accessible historic copper mine from mid-June to Oct. Summer hikers can take guided tours deep inside the mountain to touch the hand-carved tunnels and learn about the intense social history of the Alpine miners.
Stage 3: The Imperial Crown & an Optional Detour
As you push past the historic copper mine, the terrain opens up into a breathtaking, rugged plateau surrounded by the legendary "Imperial Crown". This amphitheater features five jaw-dropping 4,000-meter giants that frame your entire hike:
Weisshorn (4,505m): Towering majestically on your left.
Zinalrothorn (4,221m): Sitting straight ahead at the head of the valley.
Obergabelhorn (4,063m): Framing the back-right of the glacial arena.
Dent Blanche (4,357m): Standing sentinel past the glacier tongue.
Grand Cornier (3,962m): Guarding the right side of the valley walls.
Far up on the impassable cliff faces, the long-distance SAC huts (Cabane du Grand Mountet & Cabane d'Arpitettaz) are closed for winter due to avalanche risks.
However, before you lose the safety of the main path, look up to your right along the crest of the old glacial moraine to spot the Cabane du Petit Mountet (2,142m).
An Optional Winter Detour
If you want to add an extra hour of snowshoeing and some spectacular panoramic views for your day, you can take the steep winter track up to this hut. While its famous summer restaurant is closed, standing on the moraine ridge gives you a bird's-eye view of the frozen valley below.
The Transition Point
If you bypass the detour, the base of the moraine below Petit Mountet serves as a visual anchor. This is where the groomed hiking trail officially ends, and it's your cue to strap on your snowshoes.
Stage 4: Off-Piste to the Glacier Tongue
From the shadows of the moraine, step off-piste into the deep powder. Navigating this final stretch feels like exploring an uncharted polar landscape. The terrain is littered with huge rocks and giant glacial boulders half-buried under drifts of snow.
You will need to trudge carefully through rolling snow drifts, keeping a safe distance from the active rockfall zones beneath the steep walls on your right. Ahead, the massive, debris-strewn tongue of the Zinal Glacier will finally come into view…
A Note on the Shifting Caves
Glaciers are living, evolving giants. While the natural tunnels carved by summer meltwater used to extend hundreds of meters deep, the caves have not gone very far back into the glacier since roughly 2020 due to shifting glacial retreat and structural changes.
Critical Safety Warning
Even in the dead of winter, climbing up directly onto the glacier or scrambling up onto the steep moraine walls is extremely dangerous. Hidden crevasses, sudden snow bridge collapses, and unpredictably volatile rockfalls pose severe risks. Keep your exploration strictly confined to the safe valley floor boundaries at the cave openings and limit your time inside.
At the base of the glacier, switch out your snowshoes for microspikes (it's very slippery) and step inside an otherworldly realm:
Color: Natural tunnels glowing with a luminous, breathtaking sapphire-blue light.
Scale: Massive vaults of ancient, translucent ice stretch back into the glacier.
Detail: Ceilings adorned with thousands of delicate, glittering ice crystals and sometimes rocks.
Stage 5: A Loop for the Journey Home
After exploring the frozen caverns, retrace your tracks back through the deep snow of the upper valley plateau. Once you arrive back near the wooden bridge, it is useful to keep left of the bridge.
The Double-Sided Valley Hike
By staying left instead of crossing back over, you can follow the winter path down the opposite side of the Navizence river. This creates a loop rather than a straight out-and-back trek. It gives you a completely different view of the valley's landscape and lets you approach Zinal village from a fresh angle.
The return journey is entirely downhill, offering a swift and scenic descent. As dusk falls, the welcoming, warm lights of the historic village will guide you back to civilization…
Extend Your Stay: What to Do in Zinal
If you decide to stay overnight in Zinal after your glacier trek, you will find a charming Alpine village full of life. Depending on how your legs are feeling the next morning, here are the best ways to spend your second day:
Hit the High Slopes: Hop on the Zinal-Sorebois Cable Car to access over 70 km of pristine ski runs in the Zinal-Grimentz domain.
Low-Impact Valley Walks: Stroll the flat, groomed winter paths along the river toward the quiet hamlet of Mottec, or take a self-guided architectural walk past the historic, sun-blackened larch-wood chalets in the old quarter of Zinal village.
Classic Village Activities: Lace up some skates at the Patinoire Naturelle de Zinal - a stunning natural outdoor ice rink surrounded by peaks - or rent a classic wooden sled to tackle the local tobogganing hills.
Warming Up: Zinal Dining Options
After spending a day traversing freezing sub-zero trails, nothing hits the spot like hot Alpine comfort food. Zinal boasts several incredible traditional spots open during the winter season:
La Ferme: A highly rated local cozy favorite.
Hotel-Restaurant Le Besso: Located right in the village.
Pension de la Poste: A family inn featuring a rustic dining room built from salvaged old wood chalets.
Seamless Public Transport Access
Getting to Zinal without a car is an absolute breeze and a great example of Swiss transit efficiency:
By Train & Bus: Take the Swiss Federal Railway (SBB) main line train directly to the Sierre train station (Sierre/Siders). Right outside the station, hop onto the yellow PostBus (CarPostal) line 451 up the winding mountain roads to the hub at Vissoie.
The Final Connection: At Vissoie, you will do a seamless, timed transfer onto the line 453 bus directly to Zinal. Buses run reliably every hour throughout the winter season. The total trip from the valley floor in Sierre up to Zinal takes approx. 1 hour and 35 minutes of pure scenic bliss.
Essential Safety Tips
Check the Bulletins: The upper valley is highly exposed. Always check the daily avalanche risk via the local tourism office before heading out.
Hire a Guide: Because the glacier caves shift and change in structural stability every winter, hiring a local mountain guide is recommended for safe navigation.
Gear Up: Pack heavy insulated winter boots, snowshoes, trekking poles, microspikes for the ice, a headlamp, snacks and a thermos of hot tea.
Leave No Trace: The glacier is an incredibly fragile natural environment. Pack out absolutely everything you pack in (including organic waste like fruit peels). Do not touch, chip, or break off the delicate ice inside the caves.
Practice Trail Etiquette: Because the off-piste final stretch narrows into single-file tracks through the deep powder, always yield to uphill hikers when you are heading back down. Keep your voices low to preserve the natural peace of the valley.
This route has been hiked by the Author many times, but the best was on the 25th of January 2020. Note don't attempt this route too early, it's best to wait until winter is well established in January or February, and obviously never approach a glacier like this in summer - look at what happened in Arolla in 2024...
You may also find that so many people travel this route now that snowshoes are no longer necessary. Contact me by email for photos or to ask questions...
