Base in intricate maze of caves was designed to make plutonium in '60s; now it's a curiosity

A former underground nuclear base in Southwest China's Chongqing municipality reopened to visitors this week following a year of renovation work.

Now equipped with modern sound and lighting systems, 816 Nuclear Military Plant, once shrouded in secrecy, looks like a scene from a science fiction movie. It includes a nuclear science center and sections devoted to patriotic education and history.