Archnet: Online architecture library with a focus on Muslim cultures. Includes digital images from across the world.
ARTstor: Digital images of works of art and design, including painting, photography, sculpture and architecture. Images can be downloaded (with some restrictions), printed or saved.
Avery Digital Projects: Includes rare books, architectural drawings and photography, and ephemeral materials from Columbia's Avery Library.
Brooklyn Historical Society Online Image Gallery: A selection of historic images from Brooklyn.
Cities and Buildings Database: Image Collections from the University of Washington.
Digital Metro: Aggregated image database provides access to 150 image collections from NYC institutions.
Laguardia and Wagner Archives: Digital collections include images of NYCHA properties and historic images of queens.
Museum of the City of New York: Digital image collections of New York City. More than 170,000 images available digitally.
Municipal Archives: Selected digitized NYC buildings from tax photograph collections (1930s & 1980s).
New York Transit Museum Archive: Collection includes historical images of the New York Transit System.
NYPL Digital Collections: Streetscapes and Townscapes of Metropolitan New York 1860-1942.
RIBApix: Selected images from the British Architectural Library at the Royal Institute of British Architects.