The original region of the first-generation Pokémon video games is called Kanto.
Kanto contains the towns, routes, caves, seas, and islands explored in Pokémon Red, Green, Blue, and Yellow. The player's journey begins in Pallet Town and leads through eight Gym challenges before the Pokémon League.
The first-generation games do not prominently use the name Kanto in their original story. The region's name was established in later Pokémon material, especially the second-generation games, which allowed players to revisit it after completing Johto's main adventure.
This historical detail can cause confusion with Johto, the region introduced in Pokémon Gold and Silver. Kanto is also not the same as a specific city: it is the broad geographic setting containing locations such as Viridian City and Saffron City.