The idea was that you could travel to and from it as you pleased, but it could also be invaded by world-hopping explorers, so you also needed it to have some adequate defenses.
So actually, a lot like a video game setting with NPC's, bosses and enemies.
I've actually gone back and continued fiddling with mine well into recent years. I even made some new edits just now!
I decided to make this one public instead of a patron-only text doc.