onto present-day Google Map streetviews, so that you can "see" what places looked like in the past. The database includes photographs and streetviews from all over the world. I could easily waste hour after enjoyable hour browsing through this website.
The homepage gives you the option of entering a city, state, country name, or zip code. At any point, you can easily zoom in or out using the scroll button on your mouse. Click one of the little orange bubbles, and a sidebar pops up showing you which photos are available for overlay.