The first-generation Pokémon games take place in the Kanto region.
Kanto is the setting for Pokémon Red, Green, Blue, and Yellow. It contains locations such as Pallet Town, Viridian City, Pewter City, Cerulean City, and the Pokémon League. Players travel across the region while collecting Gym Badges and building a team of Pokémon.
The map was inspired in part by the real Kantō region of Japan, although the game world is fictionalized. The original games present Kanto as a connected landscape of towns, routes, caves, forests, waterways, and islands.
A historical detail often missed is that the name Kanto was not used explicitly in the first-generation games themselves. The region was later identified by name, especially in subsequent games and reference material. Kanto returned as a major playable area in Pokémon Gold and Silver after players completed the Johto portion of those games.