Designed by the architect Louis I. Kahn, the Phillips Exeter Academy Library is renowned mostly for the quality of its inner spaces. Particularly, the image of the building's central void with its large circular openings giving an insight onto the bookshelves has almost become an archetype of the library. Following the building's design process, however, we will learn how many tangible factors participated in the actual shaping of its architecture. The uniqueness of this project relies not only on embodying the idea of the library as institution, but also on the compromises the architect took as well as on the building's adjustment to its environmental setting.