Most cavers will know of the Riesending, the deepest cave in Germany at - 1149 metres, because of the epic rescue of Johann Westhauser from a remote chamber a kilometre down in 2014.
Having twice been into it for multi-day exploration trips, I can tell you it's a truly magnificent system, with well over 20km of passage to date and significant leads remaining - one of the greatest caves in Europe.
Now the Canstatt team who have pioneered its exploration for almost 20 years have made a feature length documentary, and if the trailer is anything to go by, it's going to be amazing. Thomas Matthalm (one of the Canstatt members) is the main cameraman but there are also significant contributions from Jeff Wade and Robbie Shone. It's out in Germany soon, with an English version due later in the year.
The trailer is here:https://www.kino-zeit.de/film-kritiken-trailer-streaming/das-riesending-20000-meter-unter-der-erde-2021?fbclid=IwAR1wXCc1DjRGgXjOqE7ucjagcSg488bnYDALGNyHVpQ58rVMKnH3GyQkUpY#lg=1&slide=0