Edgar Mueller drew THAT cave on the streets by Dockland. Where is Dockland? It's in London somewhere. That is CRAZY, and it took him only a WEEK to finish. Can you imagine how one can have such an eye for such a drawing? I can understand if it's a small 2D drawing on the streets but this thing is 3D and HUGE, drawing this without a  high birds eye view in a WEEK is talent.

I did a little research on Edgar and he is famous for drawing on streets. You can some a lot of his work here, but he even admitted that this is probably his best work.