A while back, maybe years, I think I remember a lot that needed to be placed at the side of the map like PEG's Area 52, and it showed a kind of an underground cave. Does anyone have any ideas on this one?
I have never come across any other building with "underground" parts except for PEG's Area 52. Are you sure you're not thinking of a mod that changes the cutaway textures on the sides of a game tile? ;) I'll have a look for you anyway. :)