Dachstein Giant Ice Cave

High inside the Dachstein massif above Obertraun, the Giant Ice Cave holds one of the most spectacular underground ice landscapes in the Alps. The visitor tour leads through a sequence of vast halls in which ice has built up for centuries: frozen floors, walls and formations, and in the Tristan Dome a mass of ice up to fifteen metres thick, crossed on a walkway suspended above an icy chasm. Lit from below, the ice glows blue and white against the dark limestone, and walking into it from a summer mountainside feels like entering another world.

The cave was known to local people before it was explored, but systematic exploration began on 17 July 1910, when Hermann and Hanna Bock and Georg Lahner pushed deep into the system for the first time. Guided tours began as early as 1912, and the cave was electrically lit by 1928. The names given to its chambers reflect the romantic mood of the early explorers: the King Arthur Dome, the Parzival Dome and the Tristan Dome, all drawn from Arthurian legend. The known passages extend for around 2.7 km, of which some 800 metres are open to visitors.

The ice exists because the cave is a natural cold trap with openings at different heights. In winter, cold outside air sinks into the lower parts while warmer cave air escapes through the upper openings; in summer the flow reverses. Ice grows mainly in spring, when meltwater seeps into the still-frozen chambers and freezes. In total the cave holds an estimated 13,000 cubic metres of ice — a store that has been measured shrinking by several centimetres a year since the early 2000s, which makes a visit today all the more poignant.

The cave lies within the UNESCO World Heritage landscape of Hallstatt-Dachstein/Salzkammergut, and the approach is part of the pleasure: the Dachstein Krippenstein cable car rises from Obertraun to the Schönbergalm station, from where a paved footpath leads to the cave entrance at about 1,420 metres. The Mammoth Cave, a second show cave, starts from the same station.

Getting there

The cave is above Obertraun on the Hallstätter See, in Upper Austria. The largest nearby town is Wels, about 74 km away, but the practical base is Obertraun or neighbouring Hallstatt, a few kilometres along the lake. The nearest airport is Salzburg (SZG), about 61 km in a straight line. Obertraun-Dachsteinhöhlen railway station is within walking distance of the valley station of the Krippenstein cable car, and buses connect Hallstatt with the valley station.