Longcheng, Mongolia
Longcheng, also called Lungcheng, Luut, or Dragon City, was an ancient city of the Xiongnu Empire in modern-day Mongolia. The site was discovered by Mongolian archaeologists in 2017, near Ulziit District in Arkhangai Province. It served as the empire's meeting place and de facto capital. This site was not permanent, rather, it was a seasonal or temporary place for high-ranking people in the empire to gather.