Sanxingdui Ruins, located on the south bank of Yazi River in Guanghan, Sichuan Province, covers a total area of 12 square kilometers, and its core area is a city site of 3.6 square kilometers. There are three existing city walls in the east, west and south and the Yueliangwan City Wall, some towering above the ground, and some only have wall foundations. How was the city wall of this ancient city, ancient country and ancient civilization site with the largest scale, longest duration and richest cultural connotation found in southwest China so far confirmed?

The cover reporter learned from the Sichuan Provincial Institute of Cultural Relics and Archaeology that many broad ridges in the site had attracted the attention of archaeologists long before the excavation of Sanxingdui "sacrificial pit".

Part of the middle section of the city wall at Sanxingdui (photographed from east to west, 1981). Photo data Sanxingdui Museum

In 1986, a large number of relics with "kingly spirit" were unearthed from the first and second sacrificial pits of Sanxingdui. At that time, there were different opinions. "Urge" must first carry out archaeological exploration on the nature of the earth ridges, mounds and other important surface objects.

1988 Sanxingdui site city wall. Photo data Sanxingdui Museum

In 1988, Chen De'an, then the head of Sanxingdui Site Workstation, led a team to dissect and excavate the Sanxingdui mound on the south side of Mamu River, and it was confirmed that the wall was constructed manually. Then, "follow the vines and touch the melon" to dissect the ridge and confirm that most of them are man-made walls.

By 1999, the East City Wall, the West City Wall, the South City Wall and the Yueliangwan City Wall were finally confirmed, and the layout of Sanxingdui Ancient City appeared for the first time. Its large-scale can match the "momentum" of the unearthed objects from No.1 and No.2 sacrificial pits.

In order to further clarify the construction time, characteristics and the relationship between time and time of the city walls at different locations, the Sanxingdui Site Workstation succeeded the stationmaster Lei Yu to lead the team. From 2013, it began to dissect the Zhenwu Palace City Wall, Qingguan Mountain City Wall, the corner section of the western city wall, and the southern section of the Yueliangwan City Wall. It was confirmed that they formed a small Yueliangwan city surrounded by the previously excavated Yueliangwan City Wall, covering an area of about 400000 square meters, The structure of the city wall is similar to that of Baodun Ancient City. The outer side of the wall base is generally lower than the inner side. The construction of the city wall started earlier, about the time of Xia and Shang Dynasty.

At the same time, a new town, Cangbaobao Town with an area of about 80000 square meters, was identified on the east side of Yueliangwan Town. The construction of the city wall of Cangbaobao Town is different from that of Yueliangwan Town. The city wall is mostly built by piling. The city wall is later than that of Yueliangwan Town, but it was first built no later than the middle of the Shang Dynasty.

From 2015 to 2017, the eastern city wall and the western city wall were anatomized again, and it was confirmed that the wall was built from both sides to the middle, and the upper part of the city wall was built with adobe bricks, which was very rare in the construction of the city wall in the same period in China, showing a superb level of wall building technology, which was built in the same age as Cangbaobao.

After 2021, Ran Honglin, the current head of Sanxingdui Site Workstation, continued to explore the southern city wall at the southernmost side of the ancient city and the remaining Sanxingdui site city wall trenches, and confirmed that the construction method of the southern city wall is the same as that of Cangbaobao Town, which was built no later than the middle of the Shang Dynasty; The dissection and excavation of the trench accumulation shows that the city wall at Sanxingdui site was built in the same age as the east city wall.

After more than 30 years of unremitting efforts by three stationmasters, the "true face" of Sanxingdui Ancient City finally emerged: the construction of the city was not done in a day, but went through several development periods. In the first phase of Sanxingdui Site culture, namely Baodun Culture, there were large settlements here. At the latest, the Yueliangwan Town was built in the Xia and Shang Dynasties, and then moved south The east, west and south city walls, which expanded eastward to form a large city, should have been built no later than the middle of the Shang Dynasty. Almost at the same time, a warehouse and bag town was built on the east side of the Yueliangwan small town, so as to build a layout of Sanxingdui big city with the city wall as an important symbol.

Sanxingdui Ancient City, with a scale of 3.6 square kilometers, is the largest city site of the Shang Dynasty found so far in the Yangtze River basin.