The world's largest accessible ice cave system, inside the Tennengebirge above Werfen, 40 km south of Salzburg. 42 km of passages; only the first km is open. Permanent ice regardless of the season. Open May to October. Plan 3-4 hours for the full excursion.
The Story
Locals in Werfen avoided the cave entrance for centuries. The opening on the Hochkogel face let out cold air even in July, and the darkness inside ran deep. The working assumption was that it led somewhere bad.
Anton von Posselt-Czorich walked 200 m inside in 1879, wrote a brief report in an alpine journal, and was largely ignored. Alexander von Mörk found that report in 1912, gathered a team, and pushed through the ice wall that had stopped Posselt. The cave's inner structure opened: 42 km of limestone passages, of which the first kilometre stays permanently iced. Mörk died in the war in 1914. His ashes are in a niche inside the cave. The Eisriesenwelt opened for tourism on 26 September 1920, with 180 people on the first guided tour.
The ice is not glacial. It forms because of how air moves through the mountain. Cold air is heavy; it sinks into the cave in winter and stays there, freezing the meltwater that seeps down through the limestone above. The chimney effect of the passage then traps it through summer. What you see inside, frozen waterfalls, the 25 m Great Ice Embankment, the formations Mörk's team named after Norse giants, is the accumulated result of centuries of this process. The ice grows and shrinks with climate; researchers now use it as a climate record.
The cable car, built in 1955, is Austria's steepest. It climbs 500 m of altitude in 3 minutes. From the upper station, a 15-minute walk on the Panoramaweg leads to the cave entrance. Inside: 700 steps, guided tour of 75 minutes, temperature 0°C throughout.
Visiting
From Salzburg: approx. 40 km south via A10 to Werfen exit. Car park at Eishöhlenstrasse 30, approx. 5 km from the village. Shuttle bus from car park to cable car station. Cable car (Austria's steepest) to the upper station, then 15-minute walk to cave entrance. Guided tours depart regularly from 9:30 (last tour 3:45 pm). Tour duration approx. 75 minutes, 700 steps inside. Combined ticket covers cable car and cave. Bring a jacket and closed shoes: the cave is 0°C throughout, even in peak summer. Total excursion from car park and back: 3-4 hours. Combines with Festung Hohenwerfen in Werfen village for a full day. Open May to October only.