How can anyone rest while perched on a ledge or deep within a cave? See how these explorers and photographers find a way. https://on.natgeo.com/2X9YdLH

How can anyone rest while perched on a ledge or deep within a cave? See how these explorers and photographers find a way. https://on.natgeo.com/2X9YdLH 

https://twitter.com/NatGeoTravel/status/1098492541480194048