Introduction to Dahe Tangcheng: Located in the east of Dongtouqu Village, Dahe Township, Barkol, the ancient city is rectangular in shape. There is a wider city wall in the middle that divides the ancient city into two small cities in the east and west, respectively the main city and the auxiliary city. The two cities are juxtaposed from east to west. The main city is 210 meters long from north to south and 180 meters wide from east to west. The city wall is nearly 10 meters tall and 12 meters wide. There is only one door on the west wall, which is 4 meters wide. There is one horse face at the north end of the city gate and two horse faces at the south end. There are two horse faces on the north wall. There is an enemy tower in the middle of Nancheng. The east wall is the west wall of the annexed city. There is only one passage leading to the main city. There are three built-in horse faces in the annexed city, one doorway at the north end and two at the south end. There are turrets at the four corners of the city wall, and now only the northwest and southwest corners are well preserved. The attached city is located in the east, with a length of 240 meters from north to south and a width of 177 meters from east to west. The city wall is 4-5 meters high and 10 meters wide.