A quick rendering I did for a class last semester.

In case you're wondering why the base gets larger out of perspective, the bottom of the model was actually cut out along the ground. So the model ends where the ground would meet the building, not where the underground rooms and foundation would actually end. I have a copy of the terrain I made in 3D, I just didn't get it into the model for the final rendering. Sketchup actually has the ability to make 3D terrain from contour lines which is pretty cool, but I couldn't get shadows to show up on it.
As for that weird cylinder thing, it's just a generic sculpture. The project was to make a museum, not the art that goes inside it.