Board Thread:Off Topic/@comment-27447621-20160508230102/@comment-27425734-20160511005751

Humans/Faunus could be stopped by sharp rocks in the water that might deter boats, reefs, unnaturally strong currents, and other such things could help. Grimm could be stopped by bogs with sinkholes, and quicksand that would deter the Grimm from getting too close to the village; of course, that would also limit their ability to trade by land. The village could rely on trade by sea instead if it's close enough, but they'd have to offer something of value in return for trading goods (Perhaps Dust?).