Baxian Cave located in Taitung Chang-pin country, which is also a group of sea abrasion caves . Further more , this archaeological site is a part of Chang-pin culture, which is the earliest culture in Taiwan thus far . Baxian Cave has gone through crustal uplift , prehistoric culture , religious culture three kinds of period . Consequently , it’s abundant experience make us decided to investigate the only thing that never changes here – Daylight . Chao-yin cave and Baxian are the main character in stories of Taiwanese traditional legends and regions . It is located on the cliff about 30 meters high , with a semi-circular form which has natural coastal erosion platform in front of it. Owing to the sound of water in it, people called it “Chao-yin”. Yongan Cave is about 60 meters high above Chao-yin cave , it is also one of the caves where the prehistoric culture site was produced. It is famous for the scene outside the cave , which can admire the whole beautiful scenery of Pacific Ocean. Baxian Cave face the Pacific Ocean. Sunlight shines straight to the bottom of the cave in the morning . Near noon ,the sunlight enters by refracting and diffusing , lights turn into soft in the cave. In the afternoon , the diffuse of sunlight reduce , the cave turns dark as usual. Thus our design form up by two parts – Inside the cave and Entrance of the cave. By utilizing the variation of daylight , we set devices to reconstruct prehistoric culture scene and add some vision interactive . Inorganic luminophores will absorbs and stores energy during the day , while the sun is abundant . It will slowly shines after dark or under cloudy days , form a self-sufficient lighting system . Thus , we divide the cave into three parts . From day till night , with different levels of sunlight , the glowing time varies . At last ,a particular time , it will presents a whole life scene about the primitives .Remind us that light is the only everlasting thing in this moment in this space . By Using the principles of reflection and grating, two different scenes "water" and "fire" are set in the cave, both of which are inseparable from the history of Baxian Cave. The firelight is displayed deep in the cave, so that people can feel the hope even when they are in darkness. The light of the entrance illuminates the space, corresponding to the source of the night illumination of the primitive people. Since human eye can’t afford the extremely change of sunlight while entering the cave , we design a device that can help visitors to adapt the changes of light in advance . The device is extended from seahorse’s tail . The seahorse skeletal structure is a striking case of a combination “strength” and “flexibility” found in nature . It is composed of three curly photosensitive antennae , there are many metal nodes on the side of it , which are used to control the length of elastic nylon rope and from a shading net . The photosensitive antennae will pack up as the sunlight decrease , it will changed with different solar elevation angle to make the density of the grid , than the light could enter in different level .