The Volcanic Hollow is an area first introduced in Monster Hunter 4. It consists of an active volcano and the surrounding area is the Sunken Hollow after the dormant volcano becomes active and erupts. The main feature that sets the 4th Generation Volcano apart from the others is that most of the area is primarily underground. The people of Harth apparently visit the Volcanic Hollow quite often, as such, they have vast knowledge of the area and its hazards. This area is home to many powerful monsters, such as Gravios, Iodrome, and Teostra.