The structure of loess is obviously different from other soils. The vertical section of loess is self-supporting, and its section is a whole Guanghua plane, while the sections of other soils will be scattered! So people use the uprightness of loess to build caves for people to live in.

Extended data

Historical origin.

Cave dwellings generally have cliff type, sinking type and independent type. Among them, the back mountain kiln is the most widely used. It is built on the hillside, and at the edge of the original soil, there are often several steps along the mountain. The top of the lower kiln is the upper vestibule, with a wide field of vision.

Sinking cave dwelling is to dig a square pit on the spot, and then dig a cave dwelling on the inner wall to form an underground quadrangle.

Longdong Loess Plateau is the deepest loess place in the world, and Qingyang is located in the typical Longdong Loess Plateau, where there are the most densely populated caves.

Dense layers of caves, row upon row, are described as: like caves in the clouds, like pearls embedded in the Loess Plateau.

By the Zhou Dynasty, earth caves were all over the valley. The Book of Songs called it "Fu Tao Tao Cave". During the Tang and Song Dynasties, the types of caves increased and the division of labor among caves was clear. There are dark villages, bright villages and quadrangular villages. In the Ming and Qing dynasties, small castles appeared, and a group of caves or heatable adobe sleeping platforms were enclosed with tall earth walls to defend against the chaos of war, commonly known as fortresses.

Baidu encyclopedia-caves in northern Shaanxi