During a two week expedition divers were able to connect the Hirlatzhöhle (Hirltatz Cave) to the Oberer Brandgrabenhöhle (Upper Brandgraben Cave), resulting in a 100.068 m cave system.
For a long time the Hirlatzhöhle in Hallstatt was the longest cave in Austria. Currently the cave is surpassed by the 135 kms long Schönberg Cave system, located in the Toten Gebirge.
During the Christmass holidays cave diver Gerhard Wimmer was able to finally make the connection between the two caves.
The trip to the new passages takes more and more time. Currtly it takes almost a week to get to the furtest point and return. Multiple bivaoucs are necessary, add this to the low ambient temperature and the high amount of moisture in the air and you know it takes a lof of endurance.
A nice video about the discovery, in German, is available at TvThek.
Source: Gerhard's Blog & Salzburg nachrichten & TvThek