Sanxingdui was found in 1929, and the first scientific excavation was carried out in 1934. It was led by David Crockett Graham, a scholar from the United States. He was also a museum director in Chengdu. But fate, as it so often does, intervened. The decades of upheaval that followed interrupted work on the site. Its significance was not recognized until the bombshell discovery in the 1980s.

"Our archaeological investigations in Sanxingdui have never stopped," says Lei, a researcher from the Sichuan Provincial Cultural Relics and Archaeology Research Institute. "But no one really believed there could be more sacrificial pits."

Ruins of city walls, foundations and tombs have been continuously unearthed within the 12-square-kilometer area of the Sanxingdui site-the biggest prehistoric city ruins on the upper reaches of Yangtze River-which resulted in archaeologists switching their focus to look for a high-level mausoleum.

Sanxingdui, though, had more to offer.