Trübtensee

Trübtensee is a small mountain reservoir in the municipality of Guttannen, in the Bernese Oberland of Switzerland. You will also see it called Triebtenseewli or Triebtenseeli. It sits near the Grimsel Pass, in the upper Haslital valley, part of the high country often nicknamed the "water castle of Switzerland" for its chain of hydropower lakes.

What is Trübtensee?

The lake is an artificial basin covering roughly 0.1 km². Its dam was finished in the 1950s and holds about 1.1 million cubic metres of water. It is modest next to the big Grimsel dams, which is exactly why it feels quiet and uncrowded. The coordinates are about 46.553° N, 8.298° E, close to the Sidelhorn massif.

How do you get there?

No road reaches the lake. Hikers normally start at the Grimsel Pass, which is served by the mountain road from Guttannen and Innertkirchen. A popular loop climbs the Sidelhorn, then drops via Triebtenseeli and the Husegg hut back to the pass. One route description lists about 7.8 km and around 3 hours 20 minutes, graded T3, meaning a proper mountain trail that needs sure footing. On the way you pass Totensee and Jostsee, and the climb toward the Triebtenseelicke saddle follows the border with the canton of Bern.

What will you see?

The route strings together small glacial lakes and dams with wide views over the Bernese Alps and their glaciers. The Sidelhorn summit stands at 2,764 m and gives a panorama of the whole Grimsel area. The last stretches of the ascent are steep and partly pathless, and a snowfield can linger between the summit and the ridge pylon even in midsummer. Treat that section with real caution.

When should you go?

July to October is the best window, once the trails are clear of snow. Check the weather and trail conditions before setting out, because conditions above 2,000 m change fast. Pack layers, sun protection and water; there are no shops on the route itself, and the huts and restaurants are around the pass.

Who is it for?

Walkers who like alpine lakes without crowds and are comfortable on a medium-difficulty trail. If you are staying longer in the Haslital, pair the hike with other sights nearby, such as the Gelmersee with Europe's steepest funicular, or the Handegg suspension bridge.

Frequently asked questions

Where is Trübtensee? In the municipality of Guttannen, canton of Bern, near the Grimsel Pass.

Can you drive to the lake? No. The final stretch is on foot, usually starting at the Grimsel Pass.

How big is it? About 0.1 km² in area with a capacity of roughly 1.1 million m³; the dam dates from the 1950s.

When is the best time to hike there? From July to October, after the snow has cleared from the trails.