Another no pictures post. http://en.wikipedia.org/wiki/Atta_Cave (Zer Vil Be No FOTOGRAPHS In Zee Caves !!!! etc).
Video here (in German) makes no odds. https://www.youtube.com/watch?v=KsfykoVOQlw
This Drip cave complex is breathtaking, if you pass through Attendorn Western Germany take an hour out and be guided around. If you don’t understand German just look at the geology, and if you’ve been to limestone caves elsewhere you should be able to get the gist of matters.