Artilleriewerk Grimsel, Artillery fortress in Guttannen, Canton of Bern, Switzerland

Artilleriewerk Grimsel is a mountain fortress carved into the rock of Grimsel Pass, containing underground barracks, medical facilities, and gun positions. The fortification extends roughly 1 kilometer through the mountain at approximately 2000 meters elevation.

The fortress was constructed between 1941 and 1943 during World War II as part of the Gotthard Fortress defense system. It was designed to protect the Alpine region from potential threats coming from the south.

This fortress represents how Swiss military planners integrated defense infrastructure into the Alpine landscape during a critical period. The site shows how mountain engineering and strategic thinking were combined to protect the region.

The fortress is closed: it was shut in 1998, dismantled and sold to Kraftwerke Oberhasli AG in 2003, so there is no visit inside. The 450-metre winch railway for 25 people, reached from the Summerloch near the Spitallamm dam, ran last in 2004 and was then removed. Its track is still clearly visible on the slope.

The fortress housed six 15-centimeter bunker cannons positioned with separate batteries covering different strategic directions toward Italy and the Gotthard region. This gun system was designed to provide overlapping coverage across multiple approach routes.