Phong Nha cave – Discover the mysterious depth (2,5km):

The term of cave tourism in the form of “caving” is becoming popular tourism trends in the world today. However, in Vietnam this form of tourism is still new. From April 2012, Phong Nha-Ke Bang has been organizing the tourism route of “Phong Nha-Explore the mysterious depths” to meet the needs of visitors in caving. […]