The 302m-long cave is located inside Thuy Son (Water Mountain), which is one of the 5 mountains symbolising the basic elements of ancient oriental philosophy. The arches of the natural cave range from 45m to 50m, and there are impressive rock formations featuring the Buddhist perception of hell or purgatory.
The cave has 2 sets of stairs – one up to heaven, and the other down to hell. Buddhist monk Thich Hue Hung was monitoring the restoration of the cave between 2003 and 2006. In his explanation of the Buddhist philosophy of causality, he said that those who did good deeds in life would be guaranteed a trip to the cave’s ‘Thien Thai Gioi’ (Paradise) immediately upon their death, whilst anyone committing wrong or evil actions would descend to the 10 circles of hell, and especially to the ‘Nguc A Ty’ (A Ty Jail), which is the cave’s deepest point.