Hallucinatory Terrain
You make natural terrain in a 150-foot Cube in range look, sound, and smell like another sort of natural terrain. Thus, open fields or a road can be made to resemble a swamp, hill, crevasse, or some other difficult or impassable terrain. A pond can be made to seem like a grassy meadow, a precipice like a gentle slope, or a rock- strewn gully like a wide and smooth road. Manufactured structures, equipment, and creatures within the area aren't changed.
The tactile characteristics of the terrain are unchanged, so creatures entering the area are likely to notice the illusion. If the difference isn't obvious by touch, a creature examining the illusion can take the Study action to make an Intelligence (Investigation) check against your spell save DC to disbelieve it. If a creature discerns that the terrain is illusory, the creature sees a vague image superimposed on the real terrain.
Hallucinatory Terrain 5e 2024 vs. 2014 edition differences
The 2024 version specifies that creatures can take the Study action to make an Investigation check, whereas the 2014 version allows a creature to "carefully examine" and automatically attempt an Intelligence (Investigation) check. The 2024 version emphasizes the creature notices the illusion if it discerns the terrain as illusory, while the 2014 version states creatures are "likely to see through" it.