A mysterious ancient city lies hidden in the mountains of Sichuan. A kingdom that was consigned to oblivion for thousands of years until the chance discovery of a jade artefact in 1929. Since that first find, more than 10,000 unusual items have been unearthed, including curiously shaped bronze heads and masks covered in gold foil. These objects may be as archaeologically important as the Terracotta Army of Xi'an, and experts think that this may be the capital of the ancient Shu kingdom.