A pair of islands that are situated on Route 20. The two islands are shaped the same, as if they were twins.

The caves beneath the islands are full of twists and turns and have five separate floors, with multiple boulders and other natural hindrances along the way.

The Seafoam Islands are said to be the only known roost of the Legendary Pokémon, Articuno. It is also where Misty comes to train.

Since the destruction of Cinnabar Island, Blaine has moved his gym to here.