Today, our daily life depends as much on the architecture of digital data as on that of the built environment. Despite our different uses of these constructions, they pose the same questions of structure, organisation, access, pathways, visibility, protection and identity. Going beyond a consideration of their irreducible material individuality, these essays seek to examine the processes that come into play at the moment of conception in the past and the present - of some of the critical moments in the perception of these architectures.