Occasional collapses in the roof have allowed underground jungle ecosystems to form, and with them, all-new species that have never been seen anywhere else. 
Rare cave pearls, ancient fossils, and towering stalactites form around a river running through the caves, which are so large that they form their own clouds.
Now that the caves have been thoroughly explored, the government has granted tour operators permission to host treks through the caves, which have already begun operating this summer.
