The architectural heritage of the 20th century is peculiarly vulnerable; partly because modern architecture broke with tradition, it is less easily recognised as being historic and worthy of preservation. Furthermore, efforts to secure public appreciation of contemporary architecture have concentrated too narrowly on the ‘International Modern’ style at the expense of the actual diversity of this century, on certain architects at the expense of others, and on the individual building, seen by itself, at the expense of the larger environment of which it is part. To see twentieth century architecture whole, it is necessary to depend on not only buildings themselves (insofar as they survive in something like their original condition), and not only on publications (which have tended to reflect the promotion of Modernism), but also on archival sources and above all, on the private archives of architects. The value of such archives derives not only from handsome architectural drawings, which institutions are always eager to acquire, but also from account books, publicity material, models, photographs, and notebooks, and from the integrity and coherence of all this material which belongs together; it is probably the challenge represented by such a range of material which accounts for the paucity of architectural archives in the public sphere. Fortunately, a new climate of interest in architecture, which has seen the establishment of several museums of architecture and the emergence of ‘l’archivisme’ – a re-interpreting of architectural styles of the past, drawing on archival sources and influencing contemporary architectural practice via exhibition design in particular – augurs well for the future of architectural archives. In France, the Institut Français d’Architecture has been responsible for archives of 20th century architecture since 1980, and since 1988 has operated an information centre for private architectural archives in Paris and the surrounding area. Other regional architectural archives are being set up; it is to be hoped that the resulting network will help to foment a spirit which will lead to the establishment of a museum of architecture in Paris, while at the same time providing a safety-net to ensure the well-being of private architectural archives.