International Speleological Alpine Karst Group

At a Glance

ISAAK is a friendly union of cavers having the aim to explore alpine karst phenomena. Based on some members ofthe two caving clubs VHBO ("Verein fuer Hoehlenforschung Berner Oberland") and HFGKA ("Hoehlenforschergruppe Karlsruhe") ISAAK was founded in the summer 1988. The group expanded fast and today it counts more than 100 cavers from Belgium, Germany, Great Britain, Netherlands, Slovak Republic and Switzerland. Many good friendships were created in more than 30 bigger camps and countless weekend trips.

The initial exploration camp took place in the Saegistal southeast of Interlaken. Over the course of time new areas were added, e.g. Axalp, Beatenberg, Schrattenflue, Taellistock and Hasliberg (a topo map is available).

The highest cave entries are located at Taellistock in about 3000 m altitude and at Saegistal in about 2400 m altitude. The river which theoretically drains the area of Saegistal is at 600 m altitude opening a potential of 1800 m vertical cave in this area! Our deepest and largest cave in this area is The Oberlaender (entry at 2100 m altitude, 450 m deep, 1600 m long).

During the exploration of the cave Botchenhoehle (Giessbachtal) we discovered bear bones which were more than 10,000 years old. Since 1988 we have been digging in the Akkordloch (Beatenberg). This cave probably belongs to the Baerenschacht-System which is more than 59 km long and approximately 1000 m deep. Through this mega dig (120 m long) we hope to bypass a wide branching collector. Schrattenflue is the largest continuous karst in Switzerland (approximately 4 to 5 km bee-line). Our biggest cave at Schrattenflue is the cave Neuenburger Hoehle (more than 6700 m long). A tracer flow experiment was done in the Schrattenflue in 1970. The tracer appears through two springs Baetterich and Gelber Brunnen at Thuner See. The distance of 21 km (bee-line) is crossed in a short time.

If you are interested in joining us, don't hesitate to contact us. We highly welcome every interested caver. See you soon at ISAAK!