Also known as Neimingtang, it refers to the flat land surrounded by dragons and tigers in front of the cave mountain. Miao Xiyong's "Burying Wings": "Second, the land of two waters in the dragon and tiger is called Tang Ming, with a flat design." The width of Neimingtang should be moderate, not too wide. If it is too wide, it will be close to the wild. If it's wild, you can't hide the wind, and it's hard to get together without the wind. Not too tight. If it is too narrow, the weather will be cramped. If it is too cramped, there will be no luxury and grace, and the caves will not be obvious. The shape of Neimingtang is a conformal flat nest, which requires Fiona Fang to be harmonious and should not fall down. There is a saying in He Lv Manxing: "The air in front of the cave is quiet, gentle and peaceful, and it is difficult to build a tomb for morning glory, even if it is fierce in the early years." Or humble and wet, without dripping water, without being held in the round peak, without the sudden anger of evil stones. Generally speaking, there are halls outside the land of great wealth and great wealth, but there are also real dragon knots and people inside the hall. For example, the cave is tied on a high mountain, and the dragon and tiger hold it tightly and go straight to the cave, but the dragon and tiger don't hold it tightly and go straight to the water's edge, and the water rushes to the hall, making them angry and annoyed.