Route 104 is a north-south route located in west Hoenn. Its northern terminus is at the southern limits of Rustboro City. The southern extent of the route is actually located at Route 105, a water route, but the southern terminus of the main path is at the western edge of Petalburg City.

The route is divided into two halves by Petalburg Woods. The main places for catching pokemon here are the small grassy areas on southern 104 and the water on the northern side (there is a small land of grass behind a house to catch pokemon too).