Martinsloch

Martinsloch is a natural opening in the rock of Grosses Tschingelhorn in the Glar Alps. The hole passes completely through the mountain, allowing light to pass through from one side to the other.

The opening formed through natural erosion and geological processes over vast time spans. Water and the movement of rock layers carved away at the stone, creating this hole in the mountainside.

According to local tales, a strong man named Martin created the arch by widening a gap in the rocks to protect the valley from dangerous melting waters.

The site is reached via hiking trails that lead up from the valley below, where you can view the hole and observe light passing through it. The routes require standard mountain walking ability and proper footwear.

On two specific days each year, sunlight shines directly through the hole and creates a bright spot visible from the valley far below. This fleeting occurrence lasts only a few minutes but transforms this geological feature into a rare natural phenomenon to witness.

Location: Glarus

Location: Canton of the Grisons

GPS coordinates: 46.89950,9.22252

Latest update: December 7, 2025 19:27