Route 41 more or less consists only of the Whirl Islands and the surrounding area. The entrances to the four islands are unable to be penetrated until the Trainer has Whirlpool. Three of the four islands yield valuable Pokémon and items, but if the player has the Silver Wing in their Bag, Lugia can be found through the northeast portal. This route is also home to Mantine, which is only found in this area in Pokémon Gold, Crystal and HeartGold.
A Trainer may Surf around the Islands in any way they please; however, directly south of the southernmost of the Whirl Islands, the route turns due west towards Cianwood City.