Introduction to Haitou Ancient City: Haitou Ancient City is located 48.3 kilometers southwest of Loulan Ancient City. It was the second largest city in the Lop Nur area after Loulan during the Wei, Jin, Southern and Northern Dynasties. The north and south city walls are 107 meters long, and the east and west walls are about 190 meters long, with a total area of ​​about 20,000 square meters.