World Images site

Here is the description of the World Images database:

The internationally recognized WorldImages database provides access to the California State University IMAGE Project. It has just been selected by the Library of Congress for inclusion in its historic collection of Internet materials. It contains approximately 80,000 images, is global in coverage and includes all areas of visual imagery. The images can be located using many search techniques on the left hand toolbar, from QuickSearch to Advanced and ADA Searches. For convenience the images are organized into over 800 portfolios that appear alphabetically in the Portfolio List. You can use them or explore the database using Browse Collections. Here the portfolios are hierarchically organized beginning with continents and subject grouping.

My favorite starting point is often the portfolio list page here. 

Or you can do an advanced search, ADA search or take a look at community portfolios, or just browse the collections.

If you need images for historical projects or examples of things, this is a great place to start!