Kanto Route 4/Differences among generations/Generation II

In Generation II, the western portion of Route 4 was cut off and changed to an extension of Route 3. Due to this, Route 4 western entry starts at the eastern entrance of Mt. Moon, although most of the eastern portion remains the same. Along with this, the route was shortened significantly as the length between Mt. Moon and Cerulean City was slashed in half, as was the grassy area, however the layout and positioning of ledges and signposts remains mostly the same. There is no entrance to the Cerulean Cave from this route and the road is blocked off by barriers. The TM was replaced with an and three s were added to the route.

From Mt. Moon, Route 4 travels to the east, swerving to the north and the south to avoid ledges along the route. The path turns north, then east near a large clump of trees surrounding a grassy area. The route is a very strange route as the ledges form a contour down the mountainside, leading Trainers due east and then south to the end of the path and a ledge that will force Trainers to go down it into a large clump of trees surrounding a grassy area. After going down this ledge, there is no return and Trainers must go east to reach Cerulean City.