So far, I have seen many posts about abandoned and run-down buildings. I prefer something a little more upscale from time to time, thusly I link to architecture in the Modern and Post-Modern styles.
Modern
http://www.terragalleria.com/picture...-architecture/
http://jan.ucc.nau.edu/~twp/architecture/artdeco/
http://www.eveandersson.com/photos/p...oto_size=large
Post-Modern
http://jan.ucc.nau.edu/~twp/architecture/postmoderncom/