Located about 15 kilometers from the ruins of Shouchun city, the last Chu capital in Huainan, the site, which is actually a cemetery, houses more than the large No 1 tomb.

This is believed to contain not just the king's remains, but also a chariot and sacrificial pits, with smaller tombs accompanying the main tomb in an independent cemetery surrounded by a moat, that occupies an area of about 1.5 square kilometers.

The No 1 tomb is roughly square and has a tomb passage, a common Chu typology. "Based on our previous experience, large Chu tombs, while varying in level, basically adopt this format. This distinguishes them from tombs of the Qin state (another vassal state), which often have two or four tomb passages," Gong says. Rulers of the Qin state later united China and founded the Qin Dynasty (221-206 BC).

One remarkable feature of the tomb is the presence of 21 levels of inwardly recessed steps leading to the bottom. The overall structure exhibits a well-organized arrangement. "The construction of steps is also a common practice in Chu tombs, and typically, the higher the social status of the tomb's occupant, the more steps are found," Gong says.

At the heart of the tomb lies a remarkable arrangement of burial chambers laid out in a cross shape, with eight side chambers surrounding a central chamber. "The nine-chamber structure represents the highest level of burial during that era. Previously, we had discovered a maximum of seven chambers in a Chu tomb," says Xu Lianggao, a researcher with the Institute of Archaeology at the Chinese Academy of Social Sciences.