The Hailongtun Tusi Fortress, nestled in the mountains of Guizhou, China, is a remarkable historical site that was once a stronghold of the Tusi chieftains. Established in 1257, it was a military marvel with multiple lines of defense, including castles, fortresses, and passes. Despite its destruction in 1600, the fortress remains a testament to the Tusi system, a unique hereditary governance system in southwest China. Today, it is recognized as a UNESCO World Heritage Site, preserving the legacy of the Tusi culture and offering a window into China's rich historical tapestry.