During the Qin and Han Dynasties, Yangzhou was once the county magistrate of Shang Jun. However, more than two thousand years later, this Yangzhou county has left us with many suspense and mysteries. Meng Tian, the commander of Qin Dynasty, was ordered by the first emperor to build the earliest expressway in ancient China, but he was imprisoned in Yangzhou by Hu Hai II, endangering Yangzhou. Emperor Wu of the Han Dynasty visited the north and once offered sacrifices to the Yellow Emperor at Qiaoshan Mountain in the south of Yangzhou. It suddenly disappeared mysteriously in the Han Dynasty, and the county was re-established in the Northern Wei Dynasty, not in northern Shaanxi, but now in Zhengning, Gansu Province, which led to a series of mistakes in various historical and geographical masterpieces in China. Until today, experts and scholars still hold different opinions on its idea.