During autumn and winter, depending on the sun movement, it is possible to see the sunlight through a small natural hole in the mountain. This spectacular scenery can be seen several times during the winter.
The Trou de la Grand-Mère (Grossmutterloch) is a natural opening located in the Gastlosen massif. The rock forms a large opening approximately 15 metres high.
From late October to mid-February, the sun can shine directly through the Trou de la Grand-Mère. For about 30 minutes, a beam of light passes through the mountain. To have a chance of observing it, you need to choose the right viewpoint and arrive at the scheduled time. The phenomenon also depends on the weather.
To access it, the starting point is in Jaun, Kappelboden, near the Gastlosen-Express. For a relatively easy excursion, you can take the Gastlosen-Express chairlift to the upper station, then join the paths that allow you to observe the Trou de la Grand-Mère. The geological trail of the Gastlosen is also an excellent way to discover the area. It is about 8 km long and takes approximately 3 hours. Twelve panels help to understand the spectacular geological formation of the Gastlosen. Another option is the tour of the Gastlosen, a hike of about 11 km, expected to take around 4 hours. It starts and ends at the level of the Gastlosen-Express.
If you wish to stop at a refreshment point, you can visit the Chalet du Soldat or Chalet Grat to enjoy a good dish from the region!
Approximate visibility of the sunshine at the Grossmutterloch
Unter Sattel: 27.10-09.11 from 10:35 to 11:05 / 29.01-13.02: from 11:00 to 11:30
Chli Sattel: 20.11-28.11 from 10:30 to 10:45 / 15.01-20.01: from 10:45 to 11:00
Gross Rüggli: 05.12-10.01 from 10:35 to 10:55
Schattenhalb: 05.12-10.01 from 11:15 to 11:35
Jaun-Gastlosen Bergbahnen AG
Abländschenstrasse 40
1656 Jaun
