Tongwancheng (13): 100,000 cavalry, 100 zhang of ambition.

Located next to the southwest corner of the No. 1 horse face is the site of the southwest corner tower of Tongwancheng (Figures 1-3). The corner tower is a pavilion building built on the corner platform and is an important part of the ancient city wall defense project. During the war, the soldiers stationed in the corner tower could launch arrow clusters and firearms from the front, and could also cooperate with the enemy towers on both sides and the city wall front guards to kill the enemy with crossfire. After measurement, the southwest corner tower platform is widened, the height above the foundation is 26.62 meters, the bottom length is about 35 meters, and the width is about 26 meters. It is the highest point of the existing Tongwancheng site. The "Tongwancheng Inscription" (Figure 4) written by Hu Fanghui, the Zhongshu Shilang of Daxia, is included in the "Book of Jin". Among them, "Gao Yu hides the sun, and Chongyong is in the cloud" is an image description of the southwest corner tower. There are horizontal column holes and column foot holes distributed on both sides of the corner tower site. This is the first use of early Chinese wooden tendons in buildings, which mainly has two functions: one is to form tension on the wall and enhance durability; the second is to build wooden plank roads for observation and defense. The west city is the location of the palace of Helian Bobo, which is relatively intact compared to the east city. The site of the west gate urn city (Figures 5-9) has been excavated to the north of the No. 1 horse face. The urn city is a part of the ancient city defense system. Once the enemy army breaks through the outer city gate and enters the urn city, the defenders can stand high and attack with bows and crossbows, stone weapons and other weapons, causing heavy damage to the enemy. The west gate of Tongwancheng is located in the south of the west wall of the west city, 204 meters away from the outer end of the southwest corner of the west city. The urn city is 30 meters long, 20.7 meters wide, and 10 meters deep. The bottom is 27.6 meters long and 16.3 meters wide. Archaeologists have cleaned up a Sui Dynasty tomb, a urn coffin, and more than 10 ash pits from the 8-meter-thick quicksand accumulated in the west gate urn city site. In addition, a well was found. The drilling depth was 13 meters and the bottom was not seen. At present, 4 meters have been cleaned. A square ash pit earlier than the age of the Tongwancheng city wall was found at the bottom of the urn city. From the excavation situation, at the latest in the Sui Dynasty, the urn city gate had collapsed, the city gate was blocked by rammed earth blocks, and the urn city became a ruin. According to historical records, Helian Bobo named the four city gates of the west city respectively. The east gate is "Zhao Wei", the south gate is "Chao Song", the west gate is "Fu Liang", and the north gate is "Ping Shuo". His ambition to swallow the mountains and rivers and calm the world is clear. Near the site of the "Fu Liang" gate, there is a huge scenic area guide map (Figure 10), which includes a brief introduction to the history and evolution of the Tongwancheng site, as well as the overall planning of the site park, museum architecture, and site restoration research. Three major design schemes and other pictures and texts. To the east of the guide map, through a soft sandy path in the middle of the grass, you will come to a lonely pier. This is the site of Yong'an Platform (also known as Yong'an Hall) located in the south of the west city (Figures 11-13). The rammed earth platform is 21.2-26.2 meters long on all sides, and the whole is a rectangle with a long east-west and narrow north-south, with a residual height of 19 meters, which is the commanding height in the city. Assuming that the bell tower mentioned in He Bingxun's "Bing" is Yong'an Platform, then the total height at that time was about 30 meters. Historical records show that Helian Bobo died in Yong'an Hall, and Helian Chang ascended the throne in Yong'an Platform, which shows that Yong'an Platform is a very important building, and its level should not be lower than that of the Hall of Supreme Harmony in the Qing Dynasty, and its shape is high. Cultural relic workers, based on relevant historical materials, speculate that Yong'an Hall is a building with a roof top with a mixed structure of rammed earth walls and wooden beams and columns, and has formed a restoration effect map of Yong'an Platform. "Chongtai Xiaozhi, Xiuque Yunting. Thousands of pavilions are connected, and thousands of pavilions are connected." Time goes back, and we seem to see that in the autumn wind, under the hunting flag, the Huns stood on the Yong'an Platform and looked into the distance (Figure 14). The endless emptiness of the Maowusu Desert in the north is their ancient nomadic home; the Yongding River that bypasses the city and the farther south, the soil is thousands of miles, the water and grass are beautiful, and now it is also the forbidden land of Daxia. Even though, in the wilderness, thorns and thorns are intertwined, how can it resist his 100,000 cavalry and 100 zhang of ambition.