[Okay, Diana wants to point out that there's probably a world outside of this continent, almost assuredly, but... she's not going to get into that. It's just a distraction.] They used to think such things where I'm from, many centuries ago, until explorers sailed across the sea and found an entirely new world.

I don't really have any nautical talents myself, but I'm sure that there are people here with talent enough to be sailors. Perhaps there even are customary trade routes, and we've never asked.