Soleanna Forest is an Adventure Field in Sonic the Hedgehog (2006). One of three overworld area in the game, this area is an important hub for Action Stage access, Town Missions, and hidden medals.
Showcasing expansive plains and woods in the nation of Soleanna, the Forest is a wide open area encompassing various different landscapes. The huge, abandoned gorge of Kingdom Valley lies on one side, hiding the ruins of the Duke's vast palace; opposite, the forest proper descends into the watery swamplands of Tropical Jungle. Soleanna Forest bisects the two urban parts of the small nation, separating Castle Town from the New City.
Sonic fights the Egg-Genesis on the wide open plain in the center of this area.