Location from SpongeBob SquarePants by Stephen Hillenburg / Nickelodeon
A climate-controlled air dome on the ocean floor — the only place in Bikini Bottom filled with air instead of water, containing a full Texas ecosystem and one very proud squirrel.
The Treedome is Sandy's Texas on the ocean floor — a piece of home she brought down here and maintains with scientific precision. The air pressure is controlled. The temperature is managed. The oxygen comes from the oak tree and she tends it accordingly. For SpongeBob and Patrick, who need water to survive, entering the Treedome without a water helmet results in rapid desiccation. This happens at least once. They don't always learn. The dome is simultaneously Sandy's home, her lab, and her karate dojo. She practices here, invents here, and conducts experiments on willing subjects.
A large, clear airtight dome sitting on the ocean floor near Conch Street. Inside: grass, sometimes flowers, a large central oak tree providing oxygen and acorns, a picnic table, a hamster wheel, and a bird bath. Sandy's actual house is in the oak tree. The dome has a mechanism that covers it with riveted sheet metal for privacy. An airlock allows non-air-breathers to enter if they put on a water helmet.
Also known as: The Treedome, Sandy's Dome, Sandy's Treedome