Route 4 (Japanese: ４ばんどうろ Route 4) is a north-south route located in Unova. Its northern terminus is at Nimbasa City and its southern terminus is in Castelia City. This route is a desert route, and has sinking sand instead of grass.
Route 4 is a huge deserted road at the north of Castelia City. There are exits at the north and south. It starts off with a paved road which ends abruptly another fifty steps. Along the paved road are abandoned construction sites. To the west of the paved road by Castelia City's exit, there is a large cliff with two fishermans and the sea at the bottom. To the north of the cliff-lined sea, there is an another abandoned construction site, which looks like a planned community project that got scrapped due to the harsh and arid environment. In the middle of the route, there are two paved routes; one that goes north towards Nimbasa City and the other facing west and eventually north, towards Desert Resort. By this corrupted intersection, there is an overhead highway going east and west. Trucks can be seen passing through the highway.