[@oKageo] This was this best [url=http://vignette3.wikia.nocookie.net/narutofanon/images/c/ca/Simulation_Room.jpg/revision/latest?cb=20141130214427]photo[/url] I could find to describe what I'm looking for.

Basically, take that but give it a bit more of a cement underground bunker sort of feel. There's a walkway that goes all around the central area (where the simulations occur) that is glassed up and there are stairs that lead to a control room up above. 

...If that makes sense.