Gaochang Ancient City, also known as the capital protection city in Uighur, means the king city, is located 45 kilometers east of Turpan Flaming Mountain The Mumugou River Delta at the southern foot is the only place and important gateway of the ancient Silk Road. It was first built in the Han Dynasty in the first century BC. It was named after its high and open terrain and prosperous people. In 417, Gaochang City was abolished. Since the Han and Tang Dynasties, it has been a hub connecting Central China, Central Asia and Europe. Economic and trade activities were very active, and religions from all over the world were introduced into the mainland through Gaochang. Gaochang is the most active and developed place of ancient religions in the world, and it is also one of the places where the world's religious culture gathers. After more than 2000 years of wind and sun, the outline of the old city still exists, and the city walls are magnificent, standing proudly at the foot of the Flaming Mountain. The ancient city of Gaochang is grand and spectacular. The city is rectangular, with a perimeter of 5 kilometers. It is divided into outer city, inner city and palace city. The foundation of the outer wall is 12m wide and the wall is 11.5m high, built by rammers. There are nine gates in the city. There are three gates in the south, two gates in the east, two gates in the west and two gates in the north. The gate to the north of the west is best preserved. After Gaochang City was abandoned, it gradually encroached on cultivated land, and most buildings disappeared. There are still two temple sites in the southwest and southeast corner of the outer city. One temple in the southwest corner, covering an area of about 10000 square meters, is composed of a gate, a courtyard, a lecture hall, a scripture collection building, a hall, a monk's room, etc. The temple in the southeast corner still has a polygonal tower and a worship cave, which is the only place in the city where murals are well preserved. There is a small irregular square castle in the middle of the north of the inner city. The local people call it Khan Castle. In the northern palace city, there are still many tall palace bases, generally about 4 meters. It can be seen that there were four storey palace buildings at that time.
