
Name: Hang Son Doong
Location: Quang Binh Province, Vietnam
Coordinates: 17.54696024669416, 106.14398574081777
Why it's incredible: The cave is the biggest in the world and contains two jungles.
Hang Son Doong is the world's largest known cave, with enough space in some of its passages to fly a Boeing 747 airplane through them. The limestone cavern sits beneath a lush jungle in Vietnam's Phong Nha-Ke Bang National Park and hosts primeval forests that thrive thanks to giant "skylights" in the rock.