The site is located in a fishing village by the sea, which is RuoShan in WenLing. There is a special traditional culture in this area. Every time the fishermen return from the sea, the villagers will gather to play drums and dance (Da Zou Gu) at the seaside to welcome everyone. This is a moment that touched us very much. And the color of traditional dance costumes comes from the color elements at sunset, the blue on the top comes from the color of the sky, and the yellow on the bottom comes from the color of sunlight. We think that maybe we can use light and shadow to create a ritual stage for the villagers and make daylight be a part of the ritual feeling. And how we use light to promote the generation of design will be the focus of the whole scheme. The tide is linked with the moment that the fishermen return, and we choose the ebb tide, the moment that the fishermen return home, as the climax of the whole design. We chose to apply the two properties of concave mirror: assembling light and reflecting light. Most of the time, the device will be submerged by the seawater. When the seawater gradually ebbs, and fishermen return back, the seawater will be trapped in the concave surface of the device, which will reflect the daylight onto the cliff with the concave device. Everyday when the sea water is in high tide, the device will be mostly submerged. When seawater gradually ebbs, water will be trapped in device and reflect the light onto the cliff. The device are setted two paths to make good use of sunlight. First is the light go straight to the reflector and have reflection . Another one is that the light refract into interior and through the photic layer, spotlight crystal and concave mirror, reflecting out the reflector. Installed on the inner wall of the device is an embossed metal material, which refracts sunlight constantly to the reflector in the device. Make full use of the refraction principle of light to maximize the effect of the reflector and obtain better light. We used the load-bearing principle of the arched chair to find the stable point of the entire device, and added the arched element to the device form to generate the final configuration. With the change of sea level, silt will continuously flow and deposit. The hole design at the lower part of the device is helpful to reduce the accumulation of silt, and it can also settle some silt at the bottom of the device to enhance the stability of the device itself.