Located in Guazhou County, Gansu, Suoyang City, formerly Kuyu City, is a remarkable ancient Silk Road oasis and military fortress. Dating back to the Han Dynasty (111 BC), it flourished in the Tang Dynasty and was abandoned in the Ming.

A UNESCO World Heritage Site since 2014, it's one of China's best-preserved Han-Tang city ruins. The double-walled structure (inner and outer city) features a complete military defense system with 24 horse-faced ramparts and corner towers. It also boasts an intact ancient irrigation system, a marvel of medieval engineering.

Strategically positioned on the Hexi Corridor, it guarded the route between Central Plains and the Western Regions. Legend says the Tang general Xue Rengui was once besieged here. Its name derives from the local suoyang herb. Today, the ruins stand as a silent testament to the Silk Road's glory, blending military might, agricultural wisdom, and cross-cultural exchange.