A Gym is a place where Pokémon Trainers go to train their Pokémon. Just like real life gymnasiums, where one can go to work out and build physical strength, Pokémon Gyms are places where Trainers can go to sharpen their battling skills and where their Pokémon can go to gain experience.
Often specializing in a particular type, Gyms create an environment which allows Trainers to test both their skills and Pokémon against those of others. The most powerful Trainer in a given Gym is called the Gym Leader, who is revered by both the lower-ranking members of the Gym and local fans. In the games, there is a character that usually stands near the front door of each Gym, giving tips on how to beat the Gym's challenges.
Gyms that are certified by the Pokémon League are vital to a Pokémon Trainer's journey. Leagues are designed so that conventional Trainers must travel far and wide before entering a League Competition, as the only way to enter one is by gaining at least eight official Gym Badges, and there can only be one official Gym per city. Usually, the Gyms are designed to follow and suit the type that the Gym specializes in.
List of Gyms