The Historic American Buildings Survey (HABS), Historic American Engineering Record (HAER) and Historic American Landscapes Survey (HALS) from the Prints and Photographs Division of the Library of Congress.
Collection of digitized images of buildings and cities drawn from across time and throughout the world, available to students, researchers and educators.
Some of the best images from the NASA National Space Science Data Center. All the images are public domain, however you must acknowledge NASA and the NSSDC as the supplier of the images/data.
650,000 images digitized from primary sources and printed rarities-illuminated manuscripts, historical maps, vintage posters, rare prints and photographs, illustrated books, fashion plates, and other printed ephemera.
The World Digital Library provides free access to manuscripts, rare books, maps, photographs, and other important cultural documents from all countries.