The Underground Pool, or more formally known as the Cave, is an underground room that houses a swimming pool, windows, some swimming boards, and a Lifeguard chair. It does receive occasional attention from Club Penguin Rewritten via decorating the Cave during parties.
|Polar Paw Print Pin|
- During the construction of the Medieval Party 2017, a huge crate of gold was poured into the pool. There were also several barrels and a container of hot sauce next to one of them.
- During the Medieval Party 2017, the Underground Pool served as the entrance to Ye Knight's Quests. There was three gates that lead to the three knights quests. There was also tons of gold with a sign that said "Don't Touch".
- During the Music Jam 2017, the pool was replaced with an invention made by Gary called the Floor Piano 3000. It had 2 different modes that could be changed by flipping the switch on the right, a mode where you could only here what you played and a mode where you heard what everyone played. There were also some music balloons next to the Boiler Room door.
- At the Festival of Flight 2017, the windows of the room were in need of replacement and were blocked off until they got replaced. Wooden planks, a construction sign, orange cones and a table with a coffee machine, cups and water bottles surrounded the area. A sign saying "Wear a Hard Hat" was also placed here. Lights were hung from above, too.
- During The Fair 2017, a huge carousel was placed in the Underground Pool. The floor and pool below were also decorated very nicely.
- For the duration of the Halloween Party 2017, the pool's water was replaced with slime as told by a sign in the room. Other decor included pumpkin lights and jack-o-lanterns.
- During the Christmas Party 2017, The room was turned into a completely icebound cave; with the windows now replaced with ice patches peering into the frigid waters and the pool being frozen over. For some reason, the ladder connecting to the Plaza was absent. This may be since the ladder was frozen over.
- During the Puffle Party 2018, it was used as the black puffle domain.
- The "Go Swimming" stamp can be earned by going into the Pool and wearing the Rubber Duck. This is one of the two places in Club Penguin Rewritten that allows this, along with the Cove.
- During the Medieval Party 2017, this was one of the most significant rooms, as the Ye Knight's Quests were accessed from here.