Justin and I were talking about Yinfara a little bit on IRC when this idea popped into my head: an island very large with a small community on the shore (possibly fishing-community).
Here are the main ideas:
Big island, small-ish explorable area
Explorable area consists of: sandy beach, clearings with huts in them, light forest, dense forest.
Wandering very far into the forest is limited by river and other natural means (or at least by non-insane means).
Here's a little map a drew up just now. Yes, I know my mountain-shadows aren't the best.
http://i240.photobucket.com/albums/ff23 ... ap1224.jpg
As you can see the river can only be part of the barrier. Feel free to put down your ideas for what the barrier for the non-river part should be.