Hang En (Swallow Cave)
ĐT562, Thượng Trạch, Bố Trạch, Quảng Bình, Vietnam
Hang En is the third largest cave in the world, after Hang Sơn Đoòng in the same national park, and Deer Cave in Malaysia. The only ways to reach the cave are by helicopter, or an approximately four-hour jungle trek from the nearest road.
Location of Hang En (Swallow Cave)