While piddling about on Wikipedia, I ran across this awesome website, The Berlin City Map Archive. It has detailed maps of Berlin starting in 1738 and ending in 1989 before the Wall came down. Unfortunately, there is no map after '89 of the unified Berlin, and it's not the most user-friendly map site you've been to. Still, it's pretty damn cool.
Begin with 1738 here.
Or check out the English homepage with links to additional information about the project and author, as well as more Berlin sites.
Way to Break My Balls, David Foster Wallace
3 years ago