Thien Duong Cave, Paradise Cave, is a cave in Phong Nha-Ke Bang, Quảng Bình Province, Vietnam, 450 km south of Hanoi. The cave is 31km long, the longest cave in Asia. It was found by a local man in 2005, British scientists explored the whole cave from 2005—2010. The access road to the cave was built and finished in September 2010. Tourists can go 1km into the cave.