CHONGQING, China, Nov. 6 (UPI) -- Tourists are now welcome at a former top-secret underground plutonium and weapons processing plant, turned into a three-hour neon museum tour of China's nuclear weapons history.
The site, known as China 816 Nuclear Military Plant, is in the mountains of Fuling district and was once an industrial base for raw nuclear material. The plant could withstand a magnitude-8 earthquake – or an atomic explosion on the surface.
It was built to produce plutonium-239 for weapons, but the government prevented the plant from going into operation in 1984 as construction neared completion.
"This base has never been put into operation or stored any nuclear material," Yang Yan, an administrator at the site, said to China Daily in late September. "There is no need to worry about radiation. It is safe to enter."
A UPI photographer toured the bunker Saturday.
Since its declassification in 2002, the plant now includes a modern sound and lighting system with a nuclear science center and other exhibits devoted to patriotic education and history.
It covers 104,000 square feet in 18 caves and 130 tunnels.
"A tour takes three hours," Yang said. "Visitors must follow the guide; otherwise they will get lost in this huge mazelike cave."
A small area of the plant was opened briefly to Chinese citizens only in 2010. Even now, only a third of it is open.
Construction began in 1966 as part of the Third Front Movement, a national industrial development drive on the Chinese mainland.
More than 60,000 soldiers were involved in the construction and at least 100 died in the process.