The arrow and spiral are hints to the right path.
Tan Desert is a world accessible from the Lamp Passage.
The Tan Desert is a large expanse of tan-colored sand and rocks scattered all over the place, over an abstract background spanning the outskirts. Though there are not much points of interests here, there is a portal to the Evergreen Woods, which can only be used upon solving a puzzle.
Solving the puzzle is done through following a spiral path similar to the pattern near the world's entrance, starting from the rock from the south, then cycling over each direction starting from the west afterwards, eventually leading to the portal.