The ancient city ruins of Milan in Ruoqiang county, Xinjiang Uygur autonomous region, are a well-preserved complex from the Western Han (206 BC-AD 24) to the Tang (618-907) dynasties.

The site sits at the intersection of Lop Nur, a former salt lake that has largely dried up, and the Altun Mountains. According to the official guide, it was once a key gateway along the southern routes of the ancient Silk Road and an important stronghold from which central Chinese dynasties could govern. The name Xiyu, meaning western regions, represents present-day Xinjiang and parts of Central Asia.