Professor Oak's Laboratory/Anime/Main series/Structure/Superstructure

The Oak Corral is a natural environment for Pokémon development. It is divided into regions according to type; there are areas that are perfect for Rock Pokémon, desert areas for Ground and Fire types, grassy regions, and several lakes. Sometimes the Pokémon don't get along; for this reason, some Pokémon, such as Ash's Bulbasaur, act as mediators between quarreling Pokémon.