Yumen Pass, Mountain pass near Dunhuang, China

Yumen Pass, also called Small Square Plate City, is a square walled enclosure of rammed earth about 10 metres high, with four gateways, covering more than 600 square metres at an elevation of 1,400 metres. It lies about 80 kilometres northwest of Dunhuang, with the Shule River less than 100 metres beyond its north gate.

Emperor Wu of the Han Dynasty ordered construction of this mountain passage in 121 BCE to control trade routes and defend against nomadic tribes. The structure became a crucial border post on the empire's western frontier during the early imperial period.

The name Yumen means Jade Gate, reflecting the precious stones traded from the Hotan region through this mountain passage to central China. The site reveals how trade shaped the region's cultural connections across distant territories.

The mountain passage is best reached through organized tours departing from Dunhuang, which serves as the main base for visiting. The terrain is open and expansive, so visitors should bring comfortable footwear and sun protection for their exploration.

The site spans a vast area with Han Dynasty remnants scattered across the landscape, revealing the scale of military presence once stationed here. These widespread ruins provide insight into the extensive infrastructure required to protect and manage the trade routes effectively.