On the afternoon of September 20, it was cloudy and windy. Tongwan Ancient City is also a closed scenic area, and by car, you can only get within 1.5 kilometers at most. Fortunately, the view here is extremely open, so even taking off a drone 1.5 kilometers away can clearly capture the entire layout of Tongwan Ancient City, with excellent signal. The walls of Tongwan Ancient City are snow-white, with the southwest and northwest corners being the best-preserved. We used a large drone to model the southwest corner and a smaller one for the northwest corner. From the time Helian Bobo built Tongwan City to its abandonment in the early Ming Dynasty, Tongwan City saw a thousand years of use. What we see now is likely not the original version from Helian Bobo's era, but the result of repairs and maintenance by successive dynasties.