Hallucinatory Terrain

This spell makes one 10 yard cube per level of outdoor terrain appear to be a different type (i.e. field into forest, grassland into desert, or the like). This spell requires a full turn to cast. The affected terrain looks, sounds, and smells like another type of normal terrain. The magic does not affect creatures nor any sort of fabricated item; such things retain their appearance and visibility. A save vs. Spells is allowed to see through the illusion, but only if the creatures or characters viewing the area actively attempt to do so.