From the mid-1930s till the early 1940s, initially at C.G. Jung’s request, Olga Fröbe-Kapteyn traveled to European and American libraries – in London, Paris, Rome, Munich, Zurich, Athens, Stuttgart, Oxford, Crete, Berlin, Bonn, Trier, and New York, among others – in order to pick-up symbolical images. She thus formed the Eranos Archive for Research in Symbolism. The Eranos Archive was thus intended to hold the countless photographic reproductions of images derived from Eastern and Western iconographic traditions: alchemy, folklore, mythology, and contemporary “archetypal” representations. The Eranos Archive served as an indispensable iconographic base for important studies, such as C. G. Jung’s Psychology and Alchemy (1944), Mircea Eliade’s The Forge and the Crucible—The Origins and Structure of Alchemy (1956), and Erich Neumann’s The Origins and History of Consciousness (1954) and The Great Mother—An Analysis of the Archetype (1955). In the 1950s, Olga Fröbe-Kapteyn donated the Eranos Archive to the Warburg Institute (University of London), where this extraordinary material is still kept under the name of Eranos Collection of Jungian Archetypes (only few exemplars of the original collection are in fact still preserved at Eranos). The Eranos Archive, of which some duplicates were made, also represented the basis for the Archive for Research in Archetypal Symbolism (ARAS) in New York.