Underwater is an aquatic place located on the seafloor of Club Penguin Rewritten. It can be accessed from a door in the Hidden Lake. However, the door is locked, and requires players to enter it via a different route, by playing Puffle Rescue. On the door there's a note on how to get in. Once inside, players can obtain the Moss Key Pin, and keep the door open. After obtaining the pin, it disappears from the room.