Looking at Shanhaiguan from Google Maps, can you see how important the location is?

In the past, when I looked at history, I was always interested in some passes, such as Yanmenguan, Quyongguan and Shanhaiguan. At the same time, I am also thinking: why can these passes resist the enemy from the northeast, such as Shanhaiguan, which is known as the "first pass in the world"? Later, I looked at Google Maps and saw it at a glance!

Geographical location of Shanhaiguan

"Cover yourself auxiliary pass, east enclosed mountains and seas. If you want to be heavy, you can't be the first. "

As the name implies, the word Shanhaiguan sums up all the landforms of Shanhaiguan: mountains, seas and customs.

It connects the Northeast Plain to the east and the North China Plain to the west, which happens to be the junction and throat artery of the two plains in China. The characteristics of Shanhaiguan are just the narrowest place between the two plains. It's only about ten kilometers from the seaside to Jiao Shan, the remaining vein of Yanshan Mountain.

The most widely known is Manchu customs. In fact, as early as the Ming Dynasty, Shanhaiguan's position and role were very prominent. First, it was related to the attack of outer Mongolian tribes, and then the rise of Manchu, which also directly impacted here, causing the most wars and conflicts in Shanhaiguan.

To the north of Shanhaiguan is Jiao Shan, and to the south is Bohai Bay (locally called Nanhai). Starting from the Old Dragon Head (the so-called starting point of the Great Wall) and passing through tiemenguan, you can reach the first pass and climb the Great Wall in Jiao Shan, Shunguan City. This is a complete line of defense, and you have completely mastered the transportation hub through the northeast.

Shanhaiguan defense line

The location of Shanhaiguan is actually in a corner of the corridor in western Liaoning. The so-called Liaoxi Corridor is a long and narrow transition zone between the mountains and seas in the west and the sea in the east, forming a natural traffic artery connecting North China and Northeast China.

This long and narrow corridor was actually formed by mountain weathering, rain erosion and solid matter accumulation at the seaside for millions of years, which is similar to the formation of the impact plain. If the time had been earlier, when the crustal movement had just formed a mountain range, it should have been the sea surface, while the seaside was looking for cliffs and there was no road.

Of course, it is also possible to cross mountains and mountains from North China to Northeast China, but 100,000 troops will try to cross mountains and mountains with grain and grass. Liaoxi Corridor is located between mountains and seas, with a total length of185km, the widest point of10km and the narrowest point of only a few kilometers. The destination is 10 thousand people can't force it, but one person guards it.

Shanhaiguan global map

The narrowest place in this corridor is Shanhaiguan.

In other words, when China faces the enemy from the northeast, Shanhaiguan is the last and most dangerous barrier to guard the western Liaoning corridor. We see that Jinzhou is the northernmost part of the western Liaoning corridor, which is the first line of defense. The second narrow and dangerous place in the corridor is near Huludao, which is also the second line of defense to guard the corridor. Jinzhou and Huludao were breached, leaving only Shanhaiguan. So when the enemy came from the northeast, Shanhaiguan played an important role.

On the other hand, Shanhaiguan is a narrow intersection of a prominent mountain and the sea on this slender corridor in western Liaoning. Because of the narrow passage, it is not easy for the attacker to give full play to his strength advantage when building the customs here, thus making Shanhaiguan the first customs in the world!