Wulong Karst National Park and Former 816 underground nuclear facility are in prximity, we mix\'em in one day tour and make this an extension tour of Wulong Karst Park.Former 816 underground nuclear facility was a top military secret in 1960\'s, it\'s been highly classified for years during cold war. For some reason this facility was sealed in 1984 while the construction was only 85% accomplished. This enormous confidential complex has never been actually used. Thus it\'s safe and legal to visit.This cold war facility located in a highly isolated huge mountain nearby Wulong, local civilians never been aware such an existence, even including those soldiers who did constructions for it. One thing for sure is, this is absolutely the largest artificial tunnle in this world. We focus on private tour service, make our clients travel like a local. A driver-guide who knows both Chinese culture and how to do a safe, joyful and professional guiding job will be your choice.