Pokémon Red, Green, Blue, and Yellow are set in the Kanto region.
Kanto is the setting of Pokémon’s first video game generation. Players travel through towns, routes, caves, forests, and the Pokémon League while collecting badges and completing the Pokédex.
The region includes locations such as Pallet Town, Viridian City, Pewter City, Cerulean City, and Saffron City. Its Gym Leaders include Brock, Misty, Lt. Surge, Erika, Koga, Sabrina, Blaine, and Giovanni.
Kanto is named after the real-world Kantō region of Japan, although the Pokémon version rearranges and fictionalizes its geography. Johto, introduced in Generation II, is located nearby and can be visited after the main story in Pokémon Gold, Silver, and Crystal.