“Cross Cave” is nearly as long as Mount Everest is tall—yet it’s considered a moderately sized cave for Slovenia http://on.natgeo.com/2zJF0HY

“Cross Cave” is nearly as long as Mount Everest is tall—yet it’s considered a moderately sized cave for Slovenia http://on.natgeo.com/2zJF0HY 

https://twitter.com/NatGeoTravel/status/928699310224691200