Behind the Spannagelhaus on the Hintertux glacier starts an adventure under the earth. The cave near the Spannagelhaus is unique.
With a length of 4,2 km and the deepest shaft of 25 m it is one of the most popular caves in Tyrol. A part of the cave was opened in July 1994.
A guide explains stalactites, sinters, crystals etc. and shows pictorial arts which were created by nature. The 300 million year old stones tell the story of the development of the glacier.