Where did the ancient Guanzhong area refer to?

Guanzhong area refers to Tongguan in the east, Sanguan in the west, Wuguan in the south and Xiaoguan in the north. The present Guanzhong area is located in the middle of Shaanxi Province, including five cities and one district of xi, Baoji, Xianyang, Weinan, Tongchuan and Yangling. Guanzhong is close to Qinling Mountains, and Weihe River passes through it. Rich in materials, outstanding people, surrounded by natural terrain barriers, easy to defend but difficult to attack.

Since the Warring States period, there has been a saying of "a country with four blockades" in Guanzhong area, so Zhang Liang summed up the advantages of Guanzhong with "a golden city of thousands of miles" and persuaded Liu Bang to make Guanzhong its capital.

During the Warring States Period, Zhang Yi told Qin Chen about the plan of "Lian Heng", praising Guanzhong's "fertile land, rich people, numerous chariots, tackling difficult problems in all fields, fertile land for thousands of miles, and little accumulation", and said that "this so-called rich land is also a country under the world", which was awarded the title of "Land of Abundance" much earlier than Chengdu Plain. This is because Guanzhong has become a treasure trove of geomantic omen and the capital of emperors since Zheng Guoqu was restored in the Warring States Period.

It is generally believed that there are scattered customs in the west, Hangu customs in the east, Wuguan customs in the south and Xiaoguan customs in the north, which are among the four customs. The pass extending in all directions, coupled with the two natural barriers of the northern Shaanxi Plateau and the Qinling Mountains, has made Guanzhong a battleground for military strategists since ancient times.