In 1967 China started the construction of a top secret, underground plutonium production complex in a cave underneath a mountain near Fuling in Sichuan province. The complex, known as Plant 816, was never finished; China declassified the project in 2002, and in 2010 part of the site was opened to tourism. Geospatial analysis reveals that one entrance of the Fuling facility is located at 29.55N 107.50E (see graphics below).
 Hui Zhang. “China’s HEU and Plutonium Production and Stocks,” Science and Global Security. 2011, Volume 19.P. 77.