Kristallkluft Gerstenegg

Crystal Caves at Grimsel

Useful Information

Location:	Visitor Centre Grimselwelt at the Grimsel Hospiz. From Luzern A2, A8/R4 Martisberg, Grimselstraße/R11/R6 to Grimsel Pass, turn right to Grimsel Hospitz. (46.571413, 8.331217)
Open:	Besucherzentrum Grimsel Hospiz: JUN to OCT daily. Kraftwerksführung Hospiz «Grimsel Undergrund»: 07-JUN to 19-OCT daily. Winterführung «Grimsel Undergrund»: 20-OCT to 14-DEC daily 12:50. 07-JAN to 06-JUN daily 12:50. Online booking mandatory. [2025]
Fee:	Besucherzentrum Grimsel Hospiz: free. Kraftwerksführung Hospiz «Grimsel Undergrund»: Adults CHF 38, Children (6-15) CHF 26. Winterführung «Grimsel Undergrund»: Adults CHF 75, Children (6-15) CHF 65. [2025]
Classification:	Fracture Cave, Geode Power station
Light:	Incandescent
Dimension:	L=20 m.
Guided tours:	Kraftwerksführung Hospiz «Grimsel Undergrund»: D=2 h, Max=15, MinAge=6. Winterführung «Grimsel Undergrund»: D=4 h, Max=15, MinAge=6.
Photography:	allowed
Accessibility:	no
Bibliography:	H.A. Stalder, E. Rufibach, D. Forter und P. Vollenweider (1987): Die geschützte Mineralkluft an der Gerstenegg, Grimsel BE, Schweizer Strahler, Vol 7, Nr. 10, 1987, pp 433-456. Ernst Rufibach (1999): Freuden und Leiden im Leben eines Strahlers und Bergführers, Kristallmuseum Guttannen, Eigenverlag E. Rufibach. H.A. Stalder (1986): Beschreibung der geschützten Mineralkluft Gerstenegg, Grimsel, Bern, Mitteilungen der Naturforschenden Gesellschaft in Bern, Vol 43. pdf H. Nickel (1987): Eine alpine Zerrkluft am Gerstenegg, Schweiz Lapis, Jg.12, Nr.2, S.21-24.
Address:	Grimselwelt, Grimselstrasse 19, 3862 Innertkirchen, Tel: +41-33-982-26-26. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then. Please check rates and details directly with the companies in question if you need more recent info.

History

04-OCT-1974	discovered.
DEC-1974	declared a protected geologic Natural Monument by the Bern government.
1987	opened to the public.

Description

Kristallkluft Gerstenegg is probably the most exceptional natural cave of the world. It is the only accessible crystal cleft filled with quartz crystals, and is located inside the Grimsel granite massive.

The cave was formed by tectonic forces and movements which are part of the orogeny of the Alps. In an early stage of the orogeny a magma intrusion into clefts caused by the folding cooled down very slowly inside the mountains. The result was granite, where the three main components, quartz, spar and glimmer become solid, each at its own temperature. So they are separated forming rather huge crystals.

Later this intrusion was fractured by the tectonic forces, after it became hard enough to be brittle. These cracks were filled by groundwater. The granite, still containing some of its original temperature heated the water and induced thermal convection streams. The water dissolved quartz from the granite, transported it to this large cleft and redeposited the quartz in the form of continually growing quartz crystals or rock crystals.

There are three underground sites which are connected by the tunnels: pumped storage plant Grimsel 2, Kristallkluft Gerstenegg, and the Grimsel Test Site. They were operated separately at some point, but currently there is only a combo tour of the power plant and the crystal cave available. During summer the tour starts at the Visitor Centre Grimselwelt at the Grimsel Hospiz. During winter the Visitor Center is closed, but there is a single tour every day which starts at the hydroelectric power plant in Innertkirchen. In other words, during summer you drive up yourself but the tour is shorter and cheaper, during winter you are transported from the valley but the tour takes longer and is more expensive.