A metallic fence surrounds its perimeter with 44 gates equally spaced around it; this perimeter is where the shinobi entered. Inside is a river, the forest, and a tower located in the exact center; the forest's radius is about ten kilometers. Its primary function served as a testing ground for the survival and fighting skills of genin trying to become chūnin. It was a very dangerous place, filled with hordes of flora and fauna, often gigantic, poisonous — or even more likely, both — hence its name. Within the forest are several large and deadly creatures such as leeches, tigers, and bears.

Spoiler:


The tower in the center of the forest houses a large arena which is often used as another potential area for the exams. Otherwise it is also a normal building, recently used as storage for grains and other dry goods during the off seasons. It is upheld and maintained by the Chunin and Jounin of the Konohagakure.