Underground

The Underground was a party room in Club Penguin Rewritten for the stage play Norman Swarm Has Been Transformed. To find it, five penguins need to stand on a pattern of X's near a boulder, and at least one must wear a bug costume.

Trivia

 * If five penguins stood on the five X's in the room, a chest would open, revealing the Magic Phial Pin.
 * When the April Fools' Party 2020 started, it was replaced with the Desert Dimension. This was never fixed.