Hirlatzhöhle

The Hirlatzhöhle is a vast cave system inside the Dachstein massif near Hallstatt in Upper Austria. It stretches over 115 kilometres, making it Austria’s third longest cave, and plunges 1,559 metres deep, the country’s second deepest. The cave’s lowest point lies 443 metres above sea level, sixty-five metres below the surface of nearby Hallstättersee. Six entrances exist, but only one allows safe, dry access for exploration teams. The rest are either underwater or in sheer rock faces, forcing long, complex expeditions through tight passages. Explorers continue to push the cave’s limits. The Hallstatt-Obertraun Cave Association coordinates these efforts, using ladders, bridges and even controlled blasting to open routes. In 2018 a British team linked the Hirlatzhöhle to the What u Got Pot cave, adding seven thousand metres of new passages. Divers have reached eleven thousand five hundred metres from the entrance, the farthest underwater penetration ever recorded here. Yet the greatest challenge remains Dark Star, a towering shaft where loose rock blocks progress toward the unexplored Wadiland tunnel. Visitors cannot enter the cave except during January to March, when flood risks are lowest. Inside, teams follow marked routes past waterfalls and vast chambers, some large enough to hold a cathedral. The cave lies within strict nature reserves, part of the UNESCO Hallstatt–Dachstein World Heritage site. Its fragile formations and delicate ecosystems are protected, ensuring that every step deeper reveals both geological wonder and the limits of human endurance.