The terrain corresponding to the four gods is the best terrain. In the past, no matter how to build a city, a capital and a country, we must follow the corresponding principles of the four gods. The four gods correspond to "Oriental Dragon, Southern Suzaku, Western White Tiger and Northern Xuanwu". Specifically, there are rivers in the east, depressions or lakes and seas in the south, roads in the west and mountains in the north. The terrain that meets this condition is generally the most ideal terrain. In Japan, the Peace City, Peace City, Sunlight Dongzhao and Edo City in Chang 'an in the Tang Dynasty all conform to this principle.
The four imaginary animals, Qinglong, Suzaku, White Tiger and Xuanwu, are called the Four Gods. Four kinds of beasts can be seen in the murals of the ancient tomb in Nara Bird Village. The four sacred beasts are only regarded as gods guarding the southeast, northwest and all directions, and they have no special significance in themselves. In addition to the four beasts, the mural mentioned above also depicts twelve branches, which also shows the direction.
Why is it that the terrain satisfying the four gods is the ideal terrain? We can imagine it with the throne of the emperor. Behind the throne is a backrest, with armrests on both sides and room for legs in front. Behind the backrest is the north of the mountain. If there are mountains in the north of the city, it can resist the cold wind and is beneficial to defense. The handrails on the east and west sides are like barriers to protect the city from ice and snow. In addition, the spacious space left in the south is to collect sunlight to the maximum extent. In the past, the doors of many old houses in China were red, because red also represented the color of the south.