Yinxu slowly reveals its secrets

The longest road ditch stretches for 1.6 kilometers. It is 15 meters wide and up to 30 meters at its widest. Through archaeological studies this indicates that the road was originally at least 1.6 km long, Niu says.

Its surface is covered with fine sand, with many small stones and broken pottery pieces in the soil beneath. Bronze horse bridles and stone tools have also been found. In addition, a profusion of wheel ruts are still visible on the surface.

In jiaguwen, or oracle bone inscriptions, the earliest known writing system in China and which was discovered in 1899, the Shang people called their capital Dayishang, or "the grand city of the Shang Dynasty".

Since it was excavated in the 1920s, Chinese archaeologists have studied the Yinxu Ruins for nearly a century, making it a sacred place for archaeological studies in the country, and the first known site of a capital in Chinese history with documented evidence confirmed by archaeological excavations and oracle bone inscriptions. In 2006, Yinxu was listed as a UNESCO World Heritage Site.

"This is the longest known traffic artery in Dayishang discovered in the Yinxu Ruins with clearly defined ends," Niu says. "It is also the widest road ditch discovered there so far."

Due to the slight eastward deviation of the artery at its northern end to align with the orientation of previously identified Shang Dynasty structures, Niu says the roads were probably intentionally designed and built.