This is my entry for the weekly cg challenge #100 (the theme was "movie poster"), based on a book by Hugh Howey, "wool". It's a pretty good sf novel and also a good subject for this theme. I took the renamed french version "silo", that matches better for the poster (And I was reading the french version at this time, so...). Fun fact, there is really an adaptation by Ridley Scott according to wikipedia.
All the work was done in blender, rendered with cycles (1000 samples, about 7 hours to render), and 2 hours of post production in photoshop.