This project is an elderly school in Berlin, which aims to help the elderly enjoy their happy life by enhancing their sense of self-achievement through knowledge sharing with other people. This elderly school floats on top of Fennpfuhl Lake in the park, and the elderly could also enjoy poetic scenery while teaching and learning. It includes age-friendly design, participatory design, and multi-sensory design, aiming to help the elderly gain a sense of self-achievement through cross-age communication. The elderly school allows people to meet and talk, using classrooms, in-between spaces, and gardens to provide formal and random learning and communication opportunities. It also improves the self-satisfaction of the elderly in different aspects. The classroom is a teaching space that provides fixed courses where the elderly can gain a sense of self-achievement when teaching and acquiring knowledge. The in-between space is a space for people to communicate and rest, where random learning opportunities can be triggered. The indoor garden is separated by exhibition shelves, where the elderly carefully maintain the plants, and they will also feel happy in this planting space.