Excavations at the Shimao site in Shaanxi province have revealed a massive rammed-earth city wall dating back to approximately 2300 BCE. The wall, which extends for several kilometers, features advanced defensive structures including bastions and gatehouses that predate similar Chinese fortifications by nearly a millennium. This discovery challenges current theories about the origin of urban civilization in East Asia.
Within the wall, archaeologists found evidence of a highly organized social structure, including elite residences and jade-working workshops. Interestingly, the wall's foundation contains thousands of pieces of ritual jade, suggesting that the construction was as much a spiritual undertaking as it was a defensive one. The Shimao site is now considered one of the largest and most significant Neolithic settlements in the world.