Mask Island

The Unnamed Island appeared in the episode "Island Adventure". The majority of the episode took place there.

History
Steven, Lars, Sadie, and were "stuck" on the island after Sadie hid the warp pad so that Lars would not leave the island and so he would have a chance to relax. They quickly became familiar with the land, with them being able to cook and catch fish, as well as create a hut to live in.

The island consists of a giant waterfall, a lot of trees, and some crystals. Sadie also defeated an invisible gem monster that was inhabiting the island after the Crystal Gems failed to find it.