Yanjin County is located in the northeast of Yunnan Province, China, bordering Sichuan Province to the north and east. It is under the administration of the prefecture-level city of Zhaotong. Situated on the banks of the narrow Heng River valley, a tributary of the Yangtze, the town of Yanjing, Yanjin's county seat, has been referred to as the "World's …Yanjin County is located in the northeast of Yunnan Province, China, bordering Sichuan Province to the north and east. It is under the administration of the prefecture-level city of Zhaotong. Situated on the banks of the narrow Heng River valley, a tributary of the Yangtze, the town of Yanjing, Yanjin's county seat, has been referred to as the "World's Narrowest City." The buildings of the city are situated on tall pillars, which is a preemptive measure toward water-level rise during periods of heavy flooding. Videos of the city routinely go viral because of its uniqueness and the surrounding natural environment, attracting much attention to the city.