Ready for launch: The expedition members met in Hanoi ... a sinkhole inside Son Doong. Part of the cave ceiling collapsed, letting sunlight into the cave and allowing for grass and plants to ...

But researchers recently discovered the cave is even bigger than that. A diving expedition in 2019 revealed that Son Doong is ...

Take an otherworldly journey through Hang Son Doong, the world's largest cave located in Vietnam. The cave is more than 500 feet tall, 650 feet wide, and 29,500 feet long. Video courtesy of Ryan ...

This story appears in the January 2011 issue of National Geographic magazine. “Past the hand of dog, watch out for dinosaurs,” says a voice in the dark. I recognize Jonathan Sims’s clipped ...

During the 18-day expedition ... Discovered in 1992, Hang Va cave (pictured) is hydrologically connected to Hang son Doong and although much smaller, it hides a remarkable world.