That's a good question. Building big things and then planting forests on them has been a thing for me for a while (see Multi-biome Base, Plowshare Galactic Cruiser). This one started with the wheels, and then needing to come up with something to put on them. Thought about hanging some kind of castle in there, but ended up with the spherical shell. Did the landscape first, then built rooms under it. This is one of the builds that evolved a lot as I went along. Like you, I've absorbed lots of sci-fi. I guess I can't point to any one single inspiration.

Possibly the most original design I've ever seen, I absorb lots of sci fi and I couldn't label this under any genre I'm familiar with. What was your inspiration?