Wow. Ryan Deboodt took a drone inside Hang Son Doong in Vietnam, also known as the world's largest cave, and captured stunning footage that shows off a world that looks like no other. You get a sense of the size of the place -- the biggest chamber is 5km long, 200m high and 150m wide -- and you feel its beauty.
Deboodt says he filmed near the entrance of the cave and the first and second dolines, which can be considered skylights. You can see more pictures of caves on Deboodt's site here.