Today's first "before" picture comes from the Gorillas Don't Blog entry from March 24th. It shows Monorail Blue zipping over the ticket booth area in the old Disneyland parking lot in April 1962. The parking lot is gone now, but many recognizable landmarks remain today. (I couldn't stand in exactly the same spot for this photo without having a ticket booth wall in front of me.)
The next "before" shot comes from Disneyland Nomenclature's post of Dec. 12th. It shows the Disneyland Showcase (a preview center for coming attractions) and the American Egg House restaurant in 1982. I remember both with fondness. Both have now been replaced with retail shops, selling t-shirts, plush toys, etc.