The Cave So Big It Grew Its Own Jungle

In the jungle of Vietnam there is a cave so big it has its own clouds. A jumbo jet could fly through its main tunnel, a whole city block of skyscrapers would fit inside and deep under the mountain grows a real rainforest. The man who found it in 1990 walked away and forgot where it was. We climb down into Hang Sơn Đoòng, the biggest cave passage on Earth: how a river carved it, how the roof caved in and let the light and a jungle in, why clouds form underground, what lives in the total darkness beyond the skylights, and why the biggest cave in the world just got even bigger. CHAPTERS 0:00 A cave with its own clouds 0:45 The man who lost a cave 1:45 The biggest tunnel on Earth 3:27 Carved by a river 4:28 The day the sky fell in 5:56 Clouds underground 6:44 Life beyond the light 8:04 Still growing FOOTAGE Excerpts used for commentary and education: Ryan Deboodt ("Hang Son Doong – The World's Largest Cave", "Return to Hang Son Doong"), Oxalis Adventure ("A Bird's Eye View of Son Doong – FPV"), DJI Stories ("Exploring Son Doong, the World's Largest Cave"), CBS 60 Minutes ("Vietnam's Son Doong cave is big enough for a skyscraper to fit inside"), National Geographic ("Journey Through the Largest Cave in the World | Expedition Raw"). Diagrams, maps and illustrations: own motion graphics (schematic where marked).