Hoenn is the setting for Pokémon Generation III.
The region debuted in Pokémon Ruby and Sapphire, released for the Game Boy Advance in Japan in 2002. Hoenn returned in Pokémon Emerald and was later revisited through the remakes Pokémon Omega Ruby and Alpha Sapphire.
Hoenn is characterized by extensive sea routes, islands, volcanic areas, forests, caves, and a strong emphasis on weather. The generation introduced 135 new Pokémon, beginning with Treecko, Torchic, and Mudkip and ending with the Mythical Pokémon Deoxys.
Hoenn is sometimes confused with Kanto, Johto, or Sinnoh because each is a major setting in the main series. Kanto belongs to Generation I, Johto to Generation II, and Sinnoh to Generation IV. Generation III also marked a notable change in the series’ visual presentation because it moved the main games from the Game Boy Color to the Game Boy Advance.