For years I’ve been fascinated by the idea of writing a computer program to generate an image resembling the Grand Canyon. I’m still tweaking the program, but here are a few of my better efforts.
Interestingly, the programs that generate these two images are exactly the same, except for one line of code.
I won’t go into the logic, except to say that it’s based on a simulation of erosion, with the different colored layers eroding at different rates. After that, it was trying out different values for erosion resistance, numbers of iterations, and freedom of direction.
If you like this sort of thing, see also my post Sim Acadia.