The Crystal Garden is an underwater location in the moat. It is the home of Octobella and Percival.
As the name suggests, the garden contains batches of crystals and has lanterns either hanging or mounted around the area. The location is surrounded by an underwater forest that is too thick for the Gekko-Mobile to navigate through, but not the PJ Sub, most likely due to the vehicles' different sizes. In the middle of the garden is Octobella's lair, where she keeps her books and magical items. Also inside the lair is a jail to imprison her captives.