Fort No. 86 is located at the east side of north-west cape of Nangang Island, close to Furen Village. The fortress includes two main buildings for living, gathering and dining. The most special part of Fort No.86 is its observation post extending from the main building and situated at the frontier to the shore. In the center of fortress, there is a huge plain. There are complex tunnels underneath, which linking machine gun forts and artillery forts to main site. The tunnel and fortress connecting to the sea will be revealed in this project. The space will be opened and transformed into a “Sense Library” by the architect Dai-Wen HO and her team. They aim to redefine the sense interface and building material, and to create an alternative space to sense and reinterpret the environment, the nature and the artificial creation.