Axel Nixdorf (Deutschland) - 45 min
For more than 20 years, speleologists have been tracing the myth of the „Black Danube“ in Baden-Württemberg. Between Immendingen and Möhringen, the still young Danube seeps away completely for approximately 150 days per year in the permeable karst rocks and, many kilometres afterwards emerges again. Whereto does the “Black Danube” flow? Where does it emerge from the mountain? The speleologists undertake risky and perilous dives in order to explore the many kilometres long subterranean cave systems and to detect the secret of this extraordinary phenomena of a disappearing river.