The Tree House is a members-only land den that was released during October 2010. It is available in the Den Shop, where it is sold for 4,000 Gems.
The Tree House appears as a forested Den made completely of wood, set in a large tree. It has three floors with a rope ladder and rickety stairs, made by planks of wood, nailed onto the trees trunk connecting them together. There is a small stream that runs along the tree and under the rope bridge. A path leads from the rope bridge to a grassy area on the right.
- This den appears in the Meet Cosmo adventure as the home of four koalas: Tobias, Zosi, Franklin, and Gregor.
- The Leap Year Party used a background that was very similar to this den, but the party included a leaf slide from the top floor down to the grassy area.
- There was formerly a special glitch in this den where players could go anywhere, even in the little river that is with the den and decorate the very top, known as the canopy. This glitch was patched.
- Unlike many other dens, there are no unique patterns for the wallpapers and floorings that can be used on this den.