Yangzi Explorer has added in a new stop on their Yangzi River Cruise: a visit to the “816 Nuclear Military Plant”, home to the world’s largest artificial cave. A two-hour drive from Chongqing, the plant is a former top-secret Chinese nuclear bunker that’s the world’s largest man-made cave at one million square feet (or 104,000 square meters). The project was launched in 1966 a few years after China broke with the “revisionist” Soviet Union, which had helped it develop its nuclear program.
Fearing American and Russian strikes, Chairman Mao decided to bury deep in the ground a power station capable of fueling atomic weapons. It was designed to be able to withstand thousands of tons of explosives, as well as a magnitude 8 earthquake. More than 60,000 people, including many of the nation’s top scientists, engineers and soldiers, spent time at the 816 base during its nearly two-decade construction phase. The military megaproject was only declassified in 2002, and opened to the public over 40 years after it was initiated.