We all know that the only way to get under the map in Unturned is to rely on a LandscapeHoleVolume or some strange glitch like flying the rainbow car at a gazillion miles per hour (Kilometers per hour for you metric folk), but what if in UII, a building object could incorporate that into their model?
Player-made underground bunkers going for as far and as deep as you have the resources to make it, twists and turns, traps here and there. Of course this would open up the exploitation possibilities such as destroying the entrance to the base to trap any inhabitants in, as well as placing something above the door blocking any way out, but for the same reasons movies get away with wacky physics “Because it’s a movie”, then what if this was a possibility.
With building snapping, you could close off a corridor and add to it at any time, with my earlier mention of electricity and wiring, you could set up traps like an electric gate, acid spewers, trapdoors down to spikes, etc.
So take your entire base, and put in underground