Status: 03.07.2021 12:42 a.m.
It is called huge thing for a reason. Because with more than 20 kilometers it is the longest known cave in Germany. It has been explored for two decades. Most recently, researchers were there for a documentary film.
From Theresa Krinninger,
BR
Big thing: Documentary about the fascination of speleology
Theresa Krinninger, BR, daily topics 10:00 p.m., July 2nd, 2021