Light and shadow belong together. Yet the increasing number of artificial light sources on earth are resulting in continuously decreasing zones of shadow and darkness. In architecture, the growing use of glass and other translucent layers questions the very significance of shadows. Do they protect against or cause a loss of brightness? Do we even need shadows today at all? The Secret of the Shadow explores these »holes in the light« through perceptual psychology, historical accounts of their use in architectural teaching, and an overview of their role in classical modern architecture. Additionally, 50 »shadow seekers« from around the world, including Pritzker Prize-winning architects Tadao Ando and Sverre Fehn, contributed a work of their own that reveals the importance of shadows in contemporary architectural concepts.