The Son Doong cave in Vietnam is one of planet Earth’s hidden secrets. It’s the largest cave in the world, is 200m high, 150m wide, and 5km long. It’s so big that it has its own river, jungle, and climate. Now imagine the kind of footage you’re going to get when you fly a drone through there. That’s exactly how Good Morning America won the NYC Drone Film Festival for news and documentary. Check out the video below to see more.