The towering Helan Mountains stretch for more than a hundred miles from Alxa Plateau to Yinchuan Plain, with overlapping peaks. Especially on the eastern side of Helan, where they're connected to the Yinchuan Plain by a series of faults, making them even steeper and more difficult to climb. The Great Wall here is not the continuous wall that people are familiar with. Most of the wall is on the inside and outside of valleys and canyons where it is reachable by foot or on horseback. Here they carved the mountains, constructed walls, and built passes. The Great Wall is not always one tall and continuous wall. When the Great Wall was constructed in various places, many sections were built with the help of natural obstacles, like sections of the Great Wall around the Helan Mountains.
Ming Great Wall at Sanguankou in Helan Mountain by Han Ershier / TuchongSimatai Great Wall
The Helan Mountains are very steep, but the slope suddenly decreases at the Sanguankou Passes. The terrain around the passes is very open; it has been the passageway from Alxa Plateau into Ningxia Plain since ancient times. The Ming Dynasty paid special attention to the defense of the Sanguankou Passes. It is said that on just one occasion, more than 4,000 soldiers and workers were sent to repair the passes. Usually, a mid-ranked general would be stationed here with thousands of soldiers to guard it.
In the 19th year of Jiajing (1540), the Sanguankou Passes were constructed under Censor Yang Shouli and Chief General Ren Jie’s direction. Three passes were established from the east to the west. Toudaoguan was the main pass, its north and south were connected to the Great Wall's main wall. A rammed earth wall starts from the northern mountain and goes south beyond the pass. About 2.5 km west of Toudaoguan, along the highway is Erdaoguan, the second pass. To this day, there is still only a rammed earth abutment on the mountain south of the pass. After Erdaoguan, the valley gradually narrows towards the west. After about 2.5 km, the road is sandwiched between two walls, making the place hard to break through. Sandaoguan, the third pass, was here; unfortunately, none of its ruins remain today.
Ming Great Wall at Sanguankou in Helan Mountain by Tian Zhimin / TuchongSimatai Great Wall
When the Mongolian army attacked the Western Xia for the third time, it chose the Sanguankou Passes as its primary target to breach. At that time, the Sanguankou Passes were called the Keyi Gates, which means “the barbarians’ defeat”, and the Western Xia troops were stationed here. At this very place, the Mongolian army embarked on a great war with the Western Xia army. Eventually, the brave Mongolian army captured these passes and then turned the troops to march towards the capital city of Western Xia. During the Ming Dynasty, the flames of war continued burning here. When it comes to the Tongzhi period of the Qing Dynasty (1862-1874), during the Dungan Revolt throughout northwestern China, the Sanguankou Passes were also the battlefields on which the Hui people and the government armies fought many times.
Eastern Part of the Great Wall
The eastern part of the Great Wall was primarily located in the area of the Yanshan Mountains, which are the North China Plain's main shield and the only entrance connecting the Northeast China Basin and the North China Plain. If the nomadic regimes occupied this area, they would have had a foothold to attack the Central Plains. All dynasties attached a great importance to this place and regarded it as a strategic area to build the Great Wall as a defense system.
Central Part of the Great Wall
The central part of the Great Wall was located in the Yin Mountains, a strategic place for the protection of the Hetao Plain. The Hetao Plain alternated between being occupied by farming and nomadic people since ancient times. Whoever occupied the Hetao Plain – with its rich aquatic plant life – had the advantage. This area was also the area with the greatest amount of conflict and integration between nomadic and farming peoples.
Western Part of the Great Wall
To the west of the Great Wall, the Hexi Corridor and the Western Regions were also key areas for the Great Wall to protect. For the Central Plains Dynasties, the Hexi Corridor was the gateway between the east and west. Especially after the opening up of the Western Regions and the Silk Road during the Han Dynasty, this area had become more important to the Central Plains Dynasties’ foreign relations. There are several oases in the Hexi Corridor. Because of these excellent water sources, the area was very suitable for agricultural production, leading the local people to also adopt agricultural farming. It was a key area for the Central Plains Dynasties to explore the frontier and to develop its agricultural economy.