Its history as a millstone mining area can still be seen today. These millstones were much sought-after throughout the land to grind down oak bark, which was then used as a tanning agent in leatherwork. From quarry to shelter; the caves were not only used in the Second World War - the people found refuge in times of need. People are no longer looking for a hiding place but bats are looking for their peace and quiet. We observe their night-time and winter quarters with the necessary care. We already take a good look at the special features above ground before our underground adventure and we see a landscape shaped by the Fischbach Volcano. This story, which began 600,000 years ago is one of many told by our nature guide. This is great tour for all geo fans, old and young cave explorers and friends of nature.