Okay, reading Nami's lore, we know that she's waiting for somebody who carries an object called a moonstone. Seems simple enough, but some facts I'd like to point out.
1st: The moonstone is found on the "only in the towering reaches of the world"
2nd: She trades this on the night of the winter solstice.
If you're gonna ask why I pointed these specific facts out, I'd like to you remind readers that the highest point on Valoran would be Mount Targon, and lastly, that the winter solstice happens to be the day where in night is longer than day. And frankly, it's a moonstone............
In short, does Nami's race, the Marai, have anything in relation to the unknown moon-worshippers long ago?