relics unearthed in Bicun site, Xingxian county, Shanxi province, from 2200 BC to 1700 BC [Photo provided to China Daily]

This prehistoric city ruins with rigid structures demonstrated characteristics of military fortification and offered crucial clues on the mingling of various cultures across North China.

The site is about 50 kilometers from the Shimao site in Shaanxi province, a gigantic 4,000-year-old city ruins made of stone. Consequently, archaeologists considered Bicun site, also built using stones, marked the frontier of a regional power and probably played a crucial role in a complicated defensive system.

The city gates of Bicun are also among the best-preserved and most exquisitely designed prehistoric ruins of their kind ever found in China. For example, the eastern city gate, which was composed of three erected earthen mounds covered by stones, spanned 78 meters from north to south and 48 meters from east to west. The architectural complex also showcased a strong capacity to mobilize and coordinate social resources.