Have you ever walked by a busy street corner and wondered what was there 20, 30, 50, or 60 years ago? If you have, the WhatWasThere site may be able to provide you with answers. The premise of the site is simple: the team at WhatWasThere has provided a platform where anyone can upload a photograph with two tags (location and year) so that others can learn more about the built environment. Visitors can Navigate Through Time to look around at different cities or they can use the Explore Photos area to do that in more detail. Over 30,000 photos and sites are available here and the coverage is particularly strong in San Francisco, Seattle, St. Louis, Chicago, Detroit, and the Northeast.