Check out the following cartoon by Bunpei Yorifuji, Japanese illustrator and graphic designer. Read IDEA No.347 2011/06: The Garden of Bunpei Yorifuji. I found it to be really clever and interesting. When I was a kid I used to always imagine what was underneath the concrete pavement of the streets and this illustration reminded me of those memories of what was going on in my imagination. Hope you enjoy!