A friend of mine, Carl Pisaturo and I were talking this weekend about a novel idea he had with regards to city building. Carl was thinking that instead of building a city and then digging down for things like subways and etc, why not just create the holes first, by building the city on top of a gridwork of uniform prefabricated concrete forms, which would provide ample room for transportation, plumbing, etc, while leaving more of the above-ground space free for buildings and walkways.
I made a mockup of the form in Maya, with results at right. Click here to download a short animation (1.2 Megs) of a three-tiered foundation being built.