The building was from the Fieldworks 10mm range, being described as a Sci-Fi spaceport. Whatever, because quite frankly if it's Sci-Fi it's whatever I say it is. Anyway, Fieldworks are remastering this building, because it was too small to put 10mm figures inside it. I therefore got it cheap and plan to modify it to rectify the problem.
The walls you see here are 40mm high and are simply cut and stuck down with double sided sticky tape. This really was a slap it together job. As you can see from the above shot the building covers the room/basement, acting like a lid, or roof. The reason I chose 40mm for the height of the walls was to allow vehicles to enter, but not larger mechs. Though in fact a Commando battlemech can get through the entrance.
And et voila, the Fieldworks spaceport becomes the basis for one command bunker just like that. Obviously, lots of finishing work to to here, but the above was all done in about an hour's worth of fiddling around. I'll post further pictures of this project after I have textured the base to show the final effect.
And above is an aerial view of the entrance to what could be another underground secret bunker, or just a natural cave with a worn path up to the entrance.