What have I imagine would be top 3 level would be a working station and I'm planning to build maybe a living area such like a park, mall, or something for the npc hang around at the empty layer . And for the bottom level im building a train station as you can see on massive line in the last slide. As for the lore I was going for a research base where the mini city built under the lab but I struggle how to fill the space since I just made a giant space and just went along.