Tiangu·Natural Underground Gallery is found in Liuhuyu, Dongtou Township, Yishui County, Shandong Province. The scenic spot includes "Natural Underground Gallery", "Yiranju" and "Yimeng Ecological Valley", which is a relaxation and recreation center integrating underground landscapes, entertainment, residence, etc. The Natural Underground Gallery has a wide array of stalactites and stalagmites. The "Yiranju" is constructed on the mountain, with stone houses, grass houses and promenades all around the place. Shopping centers, KTVs, camping tents and other facilities are all available. In the Ecological Valley, where is good fresh air, is the perfect "natural oxygen bar".