World 10 is not in fact world 10, it feels more like Worlds 10. As in haven currently feels like a multiverse. Each map is fairly small as a result of there being more than one.
Whirlpools serve as the method of travel between the different 'maps'. At least until charter stones are up.
I've explored the borders of a couple different 'maps' and it seems that they are not connected in any way.
And where the heck are mountains! I've only found one in all my searching, and it was as small as a swamp!