The Beast's Forest is a terrain located in the Nagano Prefecture, Japan. The area is under the control of the Pussycats.
This area is the main setting of the School Trip Arc.
The Beast's Forest, as its namesake implies, consists mostly of trees that form a large, dense forest. There's also a mountain range running right next to it.
The Pussycats have an office located somewhere within the forest. Within the office, there are cabins where visitors can stay, featuring a dining hall, hot springs and dormitories.
During the School Trip Arc, the Beast's Forest was used as a boot camp for the students of Class 1-A and Class 1-B in order to improve the strength and effectiveness of their Quirks. The students first had to fight through Pixiebob's Earth Flow monsters within the forest before arriving in the Pussycats office, which served as their lodge for the trip. Pixiebob would later use her Quirk once again to build a training area for the students next to the office.
Later, the League of Villains' Vanguard Action Squad attempted a surprise strike on the Beast's Forest, taking advantage of the environment to attack the students. One part of the forest was lit on fire by Dabi, with another part being covered by Mustard's poisonous gas. The wildfire ended up being suppressed by the firemen shortly after the League retreated.