Hồ Khanh
Phạm Duy Khánh (born 1969) is a Vietnamese logger turned cave guide and conservationist from Quảng Bình Province. He is renowned as the first to discover the largest-known cave on Earth, Sơn Đoòng.
Phạm Duy Khánh (born 1969) is a Vietnamese logger turned cave guide and conservationist from Quảng Bình Province. He is renowned as the first to discover the largest-known cave on Earth, Sơn Đoòng.