Kraus Cave

Useful Information

Location: In Gams near Hieflau.
Follow road to the Nothklamm, a gorge at the western end of the village. 2 km from turn off to parking lot. 15 min walk from the parking lot, first 200 m along a single lane road, then steep uphill on a winding trail.
Open: MAY to OCT Fri-Sun, Hol 10, 12, 14, 16.
Austrian Summer School Holidays daily 10, 12, 14, 16.
Fee: Adults EUR 10, Children (6-15) EUR 5, Family (2+2) EUR 25.
Groups (10+): Adults EUR 8.50, Children (6-15) EUR 4.
Minimum fee for a tour EUR 15.
Classification: SpeleologyKarst cave
Light: LightLED Lighting
Dimension: A=620 m asl, L=340 m, T=5-8 °C, VR=24 m.
Guided tours: D=90 min. For groups over 15 persons reservation required. Tours as required, minimum 4 persons or minimum fee.
Photography: allowed
Accessibility: no, steep ascend, staircase in the cave
Address: GeoRama, Gams bei Hieflau 145, 8922 Gams bei Hieflau, Tel: +43-3633-2201-50. 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.


1838 known to the locals.
1881 systematic exploration and development by Franz Kraus.
1882 inaugurated and opened to the public.
1883 first electric light in a cave istalled, powered by a water driven generator.
1890 electric light shut down.
1913 cave received Denkmalschutz (cultural monument).
1940s show cave closed due to lack of visitors.
1964 survey by the Denkmalamt (monument comission).
1964 the fire brigade of Gams starts to manage the cave.


The Kraushöhle was named after its explorer and developer Regierungsrat Franz Kraus. He was the father of speleology in Austria. A monument to him was installed in the cliff above the cave entrance.

A winding tunnel leads down to a huge main chamber called The Ballroom, with several small and short side passages. It is a karst cave with some dripstones, but it is famous for its gypsum (CaSO4) speleothems. A nearby sulfuric spring, which was used for bathing at the beginning of the century, is a logic explanation how they were formed. Warm sulfuric water from the same source once filled the cave. The dissolved limestone and the sulfur in the water caused a chemical reaction which produced the gypsum. Latest scientific research in Lechuguilla and other caves make it very likely, that sulfur loving bacteria produced the gypsum by feeding on the sulfur.

This cave is unique in Europe: it is one of only two limestone caves with this kind of sulfuric speleothems, which is also a show cave. The other one is Grotta Grande del Vento, Genga, Italy. Similar caves are rare but can be found all over the world, and the most famous is Lechuguilla Cave.

And another strange thing: this is the very first cave in the world with electric light but most of the time it was guided with carbide lamps. The electric light was installed by Franz Kraus in 1883 and it was powered by a water driven generator, which was built at the brook below. But this early electric light did not work very well. After seven years it had to be shut down, because of technical difficulties and too high costs. The installations were removed completely and until today this cave is guided with handheld lamps. The Austrian government does not allow the installation of electric light to protect the fragile gypsum speleothems.

The cave was closed to the public, simply due to the lack of visitors. When the Denkmalamt (Monument Protection Agency) resurveyed the cave in 1964 they realized the specialty of the cave and supported the reopening of the cave. They managed the cave for half a century, always with volunteer work on non-profit basis. There was not much money to spend and so the carbide lamps became an institution. They were cheap and reliable, and the light was very good, much better than electric torches. Unfortunately the cave is now part of the new GeoPark concept and the labor intensive carbide lamps were replaced by modern LED lamps. The light is better, but the last cave with carbide light is now gone. We recommend you take a headlamp to the tour, so you do not have to carry a hand held lamp.