Beyond their often beautiful exhibition halls, many museums contain vast, hidden spaces in which objects may be stored, conserved, or processed. Museums can also include unseen archives, study rooms, and libraries which are inaccessible to the public. This collection of essays focuses on this domain, an area that has hitherto received little attention. Divided into four sections, the book critically examines the physical space of museum storage areas, the fluctuating historical fortunes of exhibits, the growing phenomenon of publicly visible storage, and the politics of objects deemed worthy of collection but unsuitable for display. In doing so, it explores issues including the relationship between storage and canonization, the politics of collecting, the use of museum storage as a form of censorship, the architectural character of storage space, and the economic and epistemic value of museum objects. Essay contributions come from a broad combination of museum directors, curators, archaeologists, historians, and other academics.