At the north of Iwagakure, there's a small forest. It's mainly fallen trees, standing trees, and giant mushrooms. It gets its name because it if you're walking in it, look out for falling trees. But Iwa kids have learnt to do that from birth, haven't they? It's pretty much a playground for them, unlike the notorious 'forest of death' from Konoha. It's probably as dangerous, though.
