The world's largest cave is located in Vietnam

In Vietnam, there is the world's largest cave, Son Doong, inside which 15 Cheops pyramids could fit. Its length is over 6.5 km, the height reaches up to 200 meters, and the width up to 150 meters. Inside flows an underground river, and the ceiling has collapsed in places long ago, allowing sunlight to penetrate and dense jungles to grow. Tours to Son Doong are entire expeditions lasting almost a week. They are conducted in groups of 10 people and charge about $3000 per person (with all slots for 2025 already booked).