A small dungeon with different kind of lower level rats.
Outside, a Warning Sign tells you the following:
Adventurers take heed: Many rats infest this dungeon. Attacking low is the only way to defend against these vermin.
During the The Hall of the Tusker King event, this dungeon was renamed from "A White Rat Nest", updated with new types of rat and the level requirement was removed. A Runed Chest was also added.