This paper presents historical background to the concept of the large-scale spatial enclosure or artificial environment. Concern is not so much with specific or immediate prototypes of current technologies as with more remote antecedents of present day ideas reaching back into most ancient times. Rather than examining performance criteria, economics, or other physical aspects, attention is focussed almost exclusively on the history of the type of vision involved. The material is divided, in discussion, into several classes or categories: I, mythological spaces and actual structures about which fantasy evolved such as caves, tombs, and church interiors; II, visionary containers, including Utopias and science fiction; III, the structural prototypes to be found in vernacular housing, ranging from troglodytes to tent-dwellers; IV, more immediate technological antecedents like the glasshouse; and V, totally conceptual or idea architecture.