In feng shui, an auspicious site refers to good ground where people and vital energy were believed to settle at ease. The first and most essential condition traditionally named is the main mountain. The main mountain is the peak that firmly supports the rear of a site, and like the back of a chair it was thought to steady the place. Only when the ridges descending from the main mountain spread out left and right as if opening their arms, embracing a sheltered stretch of flat land within their hold, was a site considered complete. An exposed and empty rear was thought to scatter energy, so the presence of a mountain backing the site was prized above all.
No account of an auspicious site omits the Four Guardian hills. These are the surrounding ridges of the four directions, likened to sacred animals: the Black Tortoise behind, the Vermilion Bird ahead, the Azure Dragon on the left, and the White Tiger on the right. When these four hills gently enclose all four sides, the rough energy from outside cannot intrude carelessly, while the good energy within is held and gathered. If any one side was too low or empty, energy was thought to leak away in that direction, so weighing the balance of all four quarters was treated as important.
The principle often cited alongside this is mountain-behind-water-ahead. It describes a configuration that turns its back to a mountain and faces water before it. The mountain behind blocks the cold wind, while the water ahead serves daily life and farming, so it was held to be an ideal arrangement for a dwelling. Two further conditions were also valued: low-front-high-rear, a terrain lower in front and higher behind that admits ample sunlight and lets water drain naturally; and narrow-entrance-wide-interior, a form whose mouth is narrow but broadens within, so that energy does not escape but gathers calmly.
The final essence of an auspicious site was held to lie in combining sheltered wind and gathered water. Sheltered wind means harboring the wind, that is, mountain forms enclosing all sides to temper cold and violent gusts. Gathered water means obtaining water, where clear streams flow nearby yet do not rush straight away but curve slowly around the site, which was prized. Only when these two are satisfied at once, gaining stability by blocking the wind and adding vitality by obtaining water, was a place called a fully complete auspicious ground.
What is striking is that these traditional conditions overlap broadly with the practical logic of settlement. A site backed by a mountain is warm because it blocks the cold northwesterly winter wind, and a site fronting water can easily obtain drinking and irrigation water. Terrain low in front and high behind drains well and resists flooding, while terrain enclosed on all sides was also favorable for protecting a village from outside threats. Thus the places the ancients regarded as auspicious and chose to settle were, in many cases, livable lands well suited to farming and settlement alike.
In this way, an auspicious site does not remain merely a spot for divining fortune; it can be seen as the wisdom of settlement, accumulated over long ages of observing nature, organized into the language of landform. To examine an auspicious site was to read the grain of land where mountain, water, wind, and sunlight come together, and within it, it is said, lies a deeply rooted traditional way of thinking that sought to live in harmony with nature.
Finally, in speaking of an auspicious site, one cannot leave out the node that lies at its very center. The node is the spot where the energy descending from the main mountain was thought to settle at last into a single point, and even within the broad embrace of an auspicious site it was seen as the most finely harbored core. People of old likened this node to the precise spot where a needle is placed, and they held the task of pinpointing exactly the one place amid a wide ground to be the hardest part of feng shui. Within the same auspicious site, the fortune of the place was thought to differ according to where the node was fixed, so finding the single point where energy gathers most fully, after examining the mountain forms and watercourses all around, was treated as the last gate in the reading of an auspicious site.