Cinnabar Island
Cinnibar Island (Japanese: グレンじま Guren Shima, also Guren Island) is a large island located off the southern coast of the Kanto region, near Pallet Town. It is home to a large volcano. Blaine is the resident Gym Leader, specializing in Fire-type Pokémon.
In the Games
The Generation I games reveal Cinnibar Island to be a technological mecca. The journals scattered about the abandonded Cinnibar Mansion suggest that Mewtwo was cloned here. The scientists at the Pokémon Lab have the ability to ressurrect Pokémon from their fossils.
By the Generation II games, the large volcano has erupted and destroyed all the buildings except for the Pokémon Center. After the eruption, the Gym was relocated to the Seafoam Islands.
In the Anime
Cinnibar Island is considered a mere beach resort in the anime. Many Trainers skip the island entirely or go there for a break from Battling. Blaine often wears a hippy disguise and runs a hotel. His Gym is located in the volcano.