Project 131

Underground Project 131 is a system of tunnels in Hubei province constructed in the late 1960s and the early 1970s to accommodate the Chinese People's Liberation Army command headquarters in case of a nuclear war. The facility was never fully completed or used, and is currently open to visitors as a tourist attraction.

Some of the signage at the site refers to the facility as Chengshuidong Tourist Area.

Source: Wikipedia