Simatai Great Wall in the reign of emperor Chenghua

From the Chenghua period (AD 1465-1487), the main project was to connect the passes with side walls. In places where the side wall is uneven, the ridge outside the side wall is shoveled into a cliff, or the flat terrain is dug into a deep trench, thus forming several barriers with the side wall, which are called slope and trench respectively. The slopes near Simatai Great Wall are all located outside the side wall of the Great Wall, and the slopes are gentle "near the top of the ridge", extending for a long distance. In addition, during this period, the cities and fortress castles in nearly border counties were renovated and reinforced.