Route 111 is a long route which has several ways to traverse it. First, you will have to take a route through Route 112 & Mt. Chimney in order to get through. The north part lacks wild Pokémon but does have numerous trainers within. In between the north and south segments of the route is the desert. This can only be entered once the Go-Goggles have been obtained but contains a variety of Pokémon and trainers. In the desert in Emerald, you may find Mirage Tower and in the south in all games, you'll find the Desert Ruins which unlocks after accessing the Sealed Chamber. In this cave, Regirock can be found after completing a puzzle. This puzzle in Ruby/Sapphire you need to move Right, Right, Down, Down and use Strength. Emerald works similar and has you move Left, Left, Down, Down and then use Rock Smash

Special Moves used in Route 111:
Surf
Rock Smash