Route 40 is a route in Johto and the first water route Trainers from New Bark Town come in contact with.This route consists of a small amount of land that is dwarfed in proportion by the surrounding ocean. All that a Trainer must do is head south, towards the Whirl Islands. The Pokémon selection in this route is equally bland, comprising only of the most commonly appearing sea route Pokémon: Tentacool and Tentacruel.

The Whirl Islands (Japanese: うずまきじま Whirlpool Islands) make up a small island chain located between mainland Johto and Cianwood City, on Route 41. Lugia can be encountered deep inside the top right island.
Named after the dangerous whirlpools that surround them, some parts of the Whirl Islands are mysterious and largely inaccessible. Children in Olivine City are told that bad kids are sent to the islands.

Route 41 is a short water route spanning the distance between Johto's Whirl Islands and Cianwood City.Route 41 more or less exists only around the Whirl Islands, whose entrances are unable to be penetrated until the trainer has HM06: Whirlpool. Even still, entering these islands is pretty fruitless without the Silver Wing, which calls out to Lugia. However, the water of this route is still home to a rare Pokémon: Mantine. 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.