The best orientation is a dwelling place with its face facing a river or a lake in the south and back against a hill in the north. Such kind of ecologically reasonable layout of cities and villages can be frequently seen even in today's China. Cold wind from the north can be kept out by mountains; rivers are useful in facilitating irrigation and aquiculture; adequate sunshine is beneficial to the growth of the crops; and lush vegetation nearby can provide firewood, preserve water sources, and regulate local microclimate.

In Chinese geomancy, the earth was always considered as the equivalent of the body of human beings. The Fengshui principle could be well understood through comparing the rules of the earth with the physical system of the human body.

Qi, deemed as the basic element of the physical world in ancient Chinese philosophy, was the essence of Fengshui. The art of Fengshui advocated there is a Qi field, sort of like a magnetic field. Fengshui practitioners sought an auspicious Qi field and strived to avoid an ominous one. There were five elements -- dragon, cave, sand, water, and orientation -- that were used to avoid ominous Qi and gain auspicious one.

To keep the Qi from the heaven and earth in harmony in the construction of a new structure, the established terrestrial vein could not be spoiled. Based on the Yin-Yang principle and the Qi principle (holding that Yuan Qi is the basic energy that a person is born with), the ancient Chinese geomancy carried the underlying idea of "Oneness of Heaven and Human Beings."

Ancient Chinese believed that celestial and terrestrial movements correlated with the life of human beings. For instance, there are five planets in the heaven and five famous high mountains in China, and human beings have five sensory organs, and five internal organs. Also, the "Ten Celestial Stems" correlates with the ten fingers of human beings.

Fengshui combines the trinity of the heaven, the earth, and humans, and seeks harmony between human fate and design, site selection, and the construction of cities, villages, and residence. It repulses human destruction of nature and stresses cohabitation with the environment, which is regarded as perfect and even mystical.

The Fengshui principle still works in modern society where abnormal climate and environmental pollution have occurred due to excessive development through the wave of industrialization and urbanization. Countries all over the world began to take measures to address issues concerning environmental deterioration.

Starting from the end of the 19th century, a campaign was launched in the United States to beautify the urban areas, and the thought of building idyllic cities emerged in Britain. The principle of seeking harmony between human beings and nature never faded away in China. Symposiums where experts tried to discuss about city planning were held in China in the 1990s. And they came to the conclusion that Fengshui was helpful in the site selection and construction of modern cities.