Prior to the Great War, the cave was used by the employees of the nearby truck stop to hide waste from inspectors. It proved to be quite successful, as the truck stop won the 2076 Trashbusters Award. By the time the Sole Survivor leaves Vault 111, it is irradiated and home to mole rats.
The mole rat den is a cave with walls that are covered with brain fungus and glowing fungus. In the central area is a small depression with a few mole rats. In a smaller back room, a glowing mole rat (level dependent) can be found.
Not only are there various explosive containers about the den, but there is also an explodable vehicle.
- A fusion core - In the room to the right of the center room.
- The Trashbusters Award note - In the same room as the fusion core on a wooden box.
- 36 brain fungus and 23 glowing fungus. These will no longer respawn after activating the Red Rocket workshop.
The mole rat den appears only in Fallout 4.