Pokémon Ruby and Sapphire are set in the Hoenn region.
Hoenn was introduced as the setting of the third-generation Pokémon games, which were released for the Game Boy Advance beginning in 2002. The region contains numerous islands, coastal routes, underwater areas, and a strong emphasis on sea travel.
Hoenn's design was based on the Japanese island and region of Kyushu, although the Pokémon version is rotated 90 degrees relative to its real-world inspiration. The games also introduced 135 new Pokémon, bringing new species, abilities, double battles, and Pokémon Contests to the series.
Ruby and Sapphire feature rival criminal teams with competing environmental goals. Team Magma seeks to expand land using Groudon, while Team Aqua seeks to expand the sea using Kyogre. Pokémon Emerald later revisited Hoenn with a storyline involving both legendary Pokémon.