Sacrificial altar among 13,000 relics unearthed at Sanxingdui archaeological site in China

A turtleshell-shaped box and a three-foot altar used to make sacrificial offerings are among a treasure trove of 13,000 relics dating back over 3,000 years discovered by archaeologists in southwest China.

The relics -- many made of gold, bronze and jade -- were unearthed in six sacrificial pits at the Sanxingdui archaeological site, near Chengdu, Chinese state media reported Monday.

Historians know relatively little about the Sanxingdui culture, which left behind no written records or human remains, though many believe it to be part of the ancient kingdom of Shu. It's hoped the latest finds will shed light on the kingdom, which ruled in the western Sichuan basin along the upper stream of the Yangtze River until it was conquered in 316 BC.