It means that the fountain facility is placed underground and the sprinklers and lights are set under a mesh cover. When spraying water, the sprayed water column is sprayed out through pavement holes such as a cover plate or granite to achieve the effect of not occupying leisure space and viewing the fountain. The pool, sprinkler, and light are hidden under the cover plate. The water column is sprayed through the small holes between the cover plates. The surface is clean and open when no water is sprayed.