The Unknown Forest

"You're not allowed to get too close to it. You can go observe it. There‘s nothin‘ against that. But uh, do not enter the Unknown Forest. That way lies only death."

The Unknown Forest is a forest that intersects with the Godscar Chasm near Hieronymous Wiggenstaff's School for Heroism and Villainy and the town of Hope. The forest is widely considered the most dangerous place on the planet and deadly to all who enter. It takes up a large part of the continent. A short way into the Unknown Forest is a tree where new students carve their name as a Rite of Passage.

As the name suggests, information on it is hard to come by, and according to Buckminster Eden, seeing something inside the forest is unheard of.

Magical Features
The forest appears darker than night, and has a heavier atmosphere. It is difficult from the outside to see anything beyond the tree-line. In one clearing within the forest, it is possible for all sentient creatures to communicate regardless of shared languages.

Inhabitants
A nameless entity with red eyes lurks deep within the forest and communicates telepathically, frightening Fitzroy and Argo away from the forest and warning Master Firbolg of danger. They state that they "just don‘t want people to get hurt anymore." In The Adventure Zone: Graduation Ep. 18: Field Trip, this entity is revealed as the Guardian of the Unknown Forest, who attempts to keep the forest and its inhabitants safe from intruders.

Breeze Through The Willow was separated from her flock after being attacked by demons in the forest, specifically quasits and shadow demons. She'd never seen demons in the forest before then, nor had anyone warned her about them.

Trivia

 * The Firbolg ain't scared of the forest. Fitzroy is scared, but he heads in anyway in Episode 10.