The Cotton Candy Forest is a setting in Adventure Time. It is part of the Candy Kingdom, and it borders the Desert of Doom. The portal to Lumpy Space, a Frog and a mushroom, is located there. Lady Rainicorn lives here in a stable. It is sometimes a minor setting used in episodes like in the "The Duke" when Finn admits the truth about the Boomerang bottle incident. In "The Other Tarts," it is briefly shown as Finn and Jake entered the desert, and when the Royal Tart Path (which goes over the forest) is first shown. It's shown that it has a river but has never been shown in an episode. It is also shown in "Bad Little Boy."
Cotton Candy Forest, the trees are really made of cotton candy.
Royal Tart Path
Lady Rainicorn's stable.
Cotton Candy Forest at Night
Cotton Candy Forest in "Bad Little Boy."