Hang Pygmy is a karst cave in the Phong Nha-Ke Bang National Park, Bố Trạch District, Quảng Bình Province, Vietnam. It is situated deep inside the park, in a remote jungle area. Hang Pygmy has been recognized by the British Cave Research Association as the world’s fourth largest cave, after Hang Sơn Đoòng in the same national park, Deer Cave in Malaysia, and Hang Én. The cave’s entrance is a limestone arch approximately 845 meters across. The height and width of this arch reach around 100 meters.
