A horizontal lead miners’ adit (a level tube driven horizontally into the slope) leads to the cavern itself, a limestone cave, 200 metres below earth. Because the small adit is always flooded, entrance to the cave is only possible by boat after descending a lengthy stairway. The cavern opens up at the end of the adit, featuring fluorspar veins, stalactites and stalagmites, and the “Bottomless Pit.”