The first hall in the cave is 30 feet high and above it there are 50 feet of stone. 27 yards further there was a cave-in. in October 1922 the cave-explorer, a mining engineer called Prof. Dr. Hans Brandt, gave the order to break a passage through the cave-in. His workers had to dig 30 feet before they found the natural course of the cave. During the next ten years the cave was extended to one mile, which can be visited up to now.

