[aw3c2]

http://www.spoon-tamago.com/2014/10/28/detailed-cross-sectio... seems to be the actual source, citylab seems just to be an aggregator.

[dang]

Thanks. Url changed to this from http://www.citylab.com/design/2014/11/rare-maps-show-life-in....

[ermias]

Thanks for pointing to the original article.