Ad*Access Project is an online image database containing over 7,000 advertisements printed in U.S. and Canadian newspapers and magazines between 1911 and 1955: http://scriptorium.lib.duke.edu/adaccess/
Archinform is one of the largest online databases for international architecture. Includes images of over 18,000 built and unrealized projects from various architects and planners: http://www.archinform.net/start.htm
Archiseek contains images from a growing number of countries: http://www.archiseek.com/ and includes:
Canada: http://canada.archiseek.com/
Cuba: http://www.archiseek.com/
France: http://www.archiseek.com/
Germany: http://www.archiseek.com/
Ireland: http://ireland.archiseek.com/
Italy: http://www.archiseek.com/
Portugal: http://www.archiseek.com/
Spain: http://www.archiseek.com/
United Kingdom: http://www.archiseek.com/
United States: http://www.archiseek.com/
Architectural Archives of the University of Pennsylvania preserves the works of more than 400 designers from the 18th century to the present: http://www.design.upenn.edu/archives/archives/index2.htm
Art and Architecture website has more than 40,000 images and a network of over half a million links: http://www.artandarchitecture.org.uk/about.html
Art Images for College Teaching (AICT) is a personal, non-profit project of its author, art historian and visual resources curator Allan T. Kohl; all images displayed on this site have been photographed on location by the author: http://arthist.cla.umn.edu/aict/html/index.html
ArtServe is a database from the Australian National University featuring art and architecture from the Mediterranean Basin, Japan and India: http://rubens.anu.edu.au/
Bluffton University has a Digital Imaging Project by Mary Ann Sullivan that includes more than 16,000 art historical images of sculpture and architecture from pre-historic to post-modern: http://www.bluffton.edu/~sullivanm/
David Rumsey Visual Collections: Over 300,000 images from a wide variety of Museums, Universities and private collections: http://www.davidrumsey.com/collections/ The site also includes access to the Catena Digital Archive of Historic Gardens + Landscapes (see below).
Catena Digital Archive of Historic Gardens + Landscapes, a digital archive of historic gardens and landscapes, and contemporary images, including plans, engravings, and photographs: http://catena.bgc.bard.edu/
Decorative Arts & Design of the 20th Century is an online database of 20th Century design: http://www.tribu-design.com/
Digital Archive of American Architecture is an online image database from Boston College, which contains 1400 images of American architecture: http://www.bc.edu/bc_org/avp/cas/fnart/fa267/
Digital Archive of European Architecture is primarily used for students at Boston College, but owner will consider use by others: http://www.bc.edu/bc_org/avp/cas/fnart/arch/default.html
Emergence of Advertising in America is a database of over 9,000 advertising items and publications dating from 1850 to 1920, illustrating the rise of consumer culture and the birth of a professionalized advertising industry in the United States: http://library.duke.edu/digitalcollections/eaa/
Emporis.com is the world's largest free-to-use website about buildings: http://www.emporis.com/en
Great Buildings Collection, a large online database of designers and structures of all kinds, includes 3D models, photographic images and architectural drawings, commentaries, bibliographies, and web links: http://www.greatbuildings.com/gbc.html
Housing Prototypes is dedicated to the study of international multi-family housing and is published free on the Internet as an information service: http://housingprototypes.org/
Library of Congress Digital Collections has a number of digital collections and services: http://www.loc.gov/library/libarch-digital.html
Library of Congress American Memory Project contains primary source materials relating to the history and culture of the United States. The site offers more than 7 million digital items from more than 100 historical collections: http://memory.loc.gov/ammem/collections/finder.html
Earthquake Engineering Online Archive includes the William Godden Structural Engineering Slide Library, the Karl Steinbrugge Image Collection, and the Jan Kozak Collection of Historical Earthquakes from the Earthquake Engineering Research Center at the University of California Berkeley: http://nisee.berkeley.edu/
The New York Public Library Digital Gallery (NYPL) provides access to over 600,000 images digitized from primary sources and printed rarities in the collections of the NYPL; includes coverage of architecture, cityscapes, infrastructure, monuments, and town life: http://digitalgallery.nypl.org/nypldigital/index.cfm
Perseus Digital Library, also known as the Perseus Hopper, is the digital library for Tufts University: http://www.perseus.tufts.edu/hopper/
Sacred Destinations is an ecumenical guide to more than 1,250 sacred sites, holy places, pilgrimage destinations, religious buildings, and sacred artworks in 61 countries around the world: http://www.sacred-destinations.com/
Society of Architectural Historians Image Exchange, a collection of digitized slides of buildings contributed by SAH members for non-profit educational use, includes a world survey set and an American survey set: http://www.sah.org/index.php?submenu=Image&src=gendocs&ref=ImageExchange&category=Main
SPIRO is the image database of the Architecture Visual Resources Library at the University of California, Berkeley: http://www.mip.berkeley.edu/spiro/
Copyright information available at: http://www.mip.berkeley.edu/spiro/spiro_help/spirocopyright.html
Structurae is an online database offering images and information on works of structural engineering around the world; all periods of history are covered: http://www.structurae.de/
University of Washington Libraries Cities and Buildings Database is a collection of digitized images of buildings and cities drawn from multiple periods and locations: http://content.lib.washington.edu/buildingsweb/index.html
VADS, the online resource for visual arts, has images available for educational use. See terms of agreement here: http://www.vads.ac.uk/common_access_agreement.html and images here: http://www.vads.ac.uk/
World Art Kiosk is an internationally recognized database that provides access to the California State University IMAGE Project. It contains nearly 70,000 images, is global in coverage, and includes all areas of visual imagery. WorldImages is accessible anywhere and images may be freely used for non-profit educational purposes: http://worldimages.sjsu.edu/
Amiens Cathedral Project: Multimedia guide to the cathedral, Columbia University: http://www.learn.columbia.edu/Mcahweb/Amiens.html
Architecture of the Getty Center, Los Angeles, CA, is an in-depth site from Reed College that contains over 800 photographs of The Getty Center intended for supplementing what has been available in publications: http://academic.reed.edu/getty/index.html
Chartres Cathedral of Notre-Dame provides access to a comprehensive collection of images and detailed descriptions of the cathedral from the Digital Research Library at the University of Pittsburgh's University Library System: http://images.library.pitt.edu/cgi-bin/i/image/image-idx?c=chartres&page=index
Couvent Dominicain Sainte-Marie de La Tourette: http://www.couventlatourette.com/
Farnsworth House website is a project by the Columbia Architecture School's Building Technologies Group: http://www.columbia.edu/cu/gsapp/BT/GATEWAY/FARNSWTH/farnswth.html
Historic Buildings In The World Trade Center Vicinity contains images, history, and information about their current status from preserve.org: http://www.preserve.org/wtc/index.htm
PatCenter by Richard Rogers / Ove Arup and Partners: Project by the Columbia Architecture School's Building Technologies Group: http://www.columbia.edu/cu/gsapp/BT/PATCENT/patmenu.html
Vézelay Benedictine Abby Church of Sainte-Marie-Madeleine is one of the most important surviving monuments of architecture and sculpture of the Romanesque period: http://images.library.pitt.edu/cgi-bin/i/image/image-idx?c=vezelay&page=index
David Rumsey Map Collection: http://www.davidrumsey.com/
Images of Early Maps on the Web: http://www.maphistory.info/webimages.html
National Atlas of the United States: http://www.nationalatlas.gov/
National Geophysical Data Center: http://www.ngdc.noaa.gov/mgg/topo/topo.html
National Parks Maps: http://www.nps.gov/carto/
New Jersey Department of Transportation Maps: http://www.state.nj.us/transportation/gis/map.shtm
New Jersey Geological Survey Geodata: http://www.state.nj.us/dep/njgs/geodata/index.htm
Oddens Bookmarks: http://oddens.geog.uu.nl/index.php
Perry-Castañeda Library Map Collection: http://www.lib.utexas.edu/maps/map_sites/hist_sites.html
Archined contains images and information about contemporary architecture in the Netherlands: http://www.archined.nl/en/
Art Nouveau World Wide is a web site dedicated to the Art Nouveau period, includes material on Berlage, Galle, Gaudi, Guimard, Hoffman, Mackintosh, and Sauvage: http://pagesperso-orange.fr/artnouveau/
California Heritage Collection is an online archive of more than 30,000 images illustrating California's history and culture, from the collections of the Bancroft Library at the University of California, Berkeley: http://www.oac.cdlib.org/about/oacprojects.html
Chicago Architects Oral History Project contains information from the Art Institute's Department of Architecture; includes transcripts from interviews and some images: http://digital-libraries.saic.edu/cdm4/index_caohp.php?CISOROOT=/caohp
Chicago Landmarks contains representative work of well-known Chicago architects, as well as maps, historic resources survey, a style guide, and more: http://www.ci.chi.il.us/Landmarks/Index.html.
Chicago Imagebase is an online database containing a wide variety of images and other data aimed at enhancing knowledge about the built environment of the Chicago region: http://tigger.uic.edu/depts/ahaa/imagebase/
Irresistible Decay: Ruins Reclaimed is a site focusing on the special collections of the Research Library at the Getty Research Institute, which examines images of ruins as both symbols of decay and emblems of continuity over time: http://www.getty.edu/research/conducting_research/digitized_collections/virtual/id/
Mexico: From Empire to Revolution is a digital Image resource from Getty Research Institute; includes cabinet cards, cartes-de-visite, albums, postcards, and other forms of photography. Images reproduced are from the exhibition Mexico: From Empire to Revolution: http://www.getty.edu/research/tools/digital/mexico/
The Missouri Digital Heritage Initiative website contains information and images from institutions across the state: http://www.sos.mo.gov/mdh/
Monuments of the Future: Designs by El Lissitzky is a digital image collection from the Getty Research Institute that includes images reproduced from the exhibition of the same name: http://www.getty.edu/research/conducting_research/digitized_collections/lissitzky/
Early Photography in Greece and the Mediterranean is a digital image collection from the Getty Research Institute containing over 560 nineteenth and early twentieth century photographs of ancient Greek and Roman architecture: http://www.getty.edu/research/conducting_research/digitized_collections/photography_greece/index.html
Nineteenth Century Views of Manhattan is the New York Public Library's online exhibition Moving Uptown: Nineteenth-Century Views of Manhattan: http://www.nypl.org/research/chss/spe/art/print/exhibits/movingup/opening.htm
Philadelphia Architects and Buildings is a database of architectural and historical information and images for 35,000+ structures, mostly in Philadelphia, Bucks, Chester, Delaware, and Montgomery Counties, including all those on the Philadelphia Historical Commission list of significant buildings, and the Pennsylvania Historical & Museum Commission's inventory of historic structures: http://www.philadelphiabuildings.org/pab/
Renaissance and Baroque Architecture / Architectural History 102 is a collection of images scanned from slides taken by Professor C. W. Westfall and used in his survey course at the University of Virginia: http://www.lib.virginia.edu/artsandmedia/dic/colls/arh102/index.html
Team 10 online: http://www.team10online.org/index.html
Canadian Centre for Architecture: http://www.cca.qc.ca/
Dutch Architecture Museum: http://dam.inm.de/
Guggenheim Museum: http://www.guggenheim.org/
Museum of Modern Art: http://www.moma.org/
Museum of the City of New York: http://www.mcny.org/
National Building Museum: http://www.nbm.org/
Netherlands Architecture Institute: http://www.nai.nl/e/collection/index.html
Skyscraper Museum: http://www.skyscraper.org/home_flash.htm
Smithsonian Institution: http://si.edu/
Vitra Design Museum: http://www.design-museum.de/
CUPOLA offers galleries of cupolas, historic architecture, art, and picturesque landscapes. Also cupola Q&A pages, state capitol building histories, wordplay, AutoCAD software resources, & killer HotLinks. Main site: http://cupola.com//
Cupola's Hot Links: http://www.cupola.com/html/hotlinks/hotarch1.htm
Solo Architectura: http://www.soloarquitectura.com/
Vitruvio is a web resource guide to architecture that includes links to major sites: http://www.vitruvio.ch/index.php
Theatre History on the Web: http://www.videoccasions-nw.com/history/jack.html