The Nack is a hilltop 867 m above sea level in front of the Hohe Fluh. In 1935, some men set out to descend into the depths of the cave in search of a skull allegedly hidden in the Nackloch. They reached a depth of 30 m without finding the legendary skull. A second expedition in 1951/52 was also unsuccessful. This time, the researchers reached a depth of 60 m according to their own measurements.
