Pokémon Red and Blue are set in the Kanto region.
Kanto is the setting for the first-generation Pokémon games and contains locations such as Pallet Town, Viridian City, Pewter City, and the Pokémon League. Professor Oak’s laboratory in Pallet Town is where the player begins the adventure.
The region includes eight Gym Leaders and a range of environments, including forests, caves, oceans, islands, and urban areas. Players travel through Kanto while earning Gym Badges, confronting Team Rocket, and working toward the Pokémon League.
Kanto is also the principal setting of the original Pokémon animated series. It is sometimes confused with the real-world Kantō region of Japan, but the Pokémon setting is a fictional game world inspired partly by geography in Japan. Later games introduced regions such as Johto, Hoenn, Sinnoh, and many others.