How about having a "top secret" subatomic research facility, on your layout; maybe, a cyclotron(an oscillating field accelerator) smashing away at atoms...
The barbwire and "top secret" signage, alone, would look quite cool. Frosted windows with strange sounds emanating from within; complete, with eerie lighting and shadows... that might might look nice? An over-the-hill O scale track-side worker, strapped onto a stainless gurney, receiving a life changing subatomic particle shower, from the resident research fiend might work, too?
There's a lot of "top secrets" that might look good, in your 1/48th world.
Rick