Seafoam Islands

25 Pokémon can be caught at Seafoam Islands in Kanto — highlighted on the map below.

The Seafoam Islands are twin isles of identical shape situated along Route 20 in Kanto, though Japanese versions treat them as a single landmass. Beneath them lies a five-floor cave system where puzzles must be solved by pushing boulders into the water with Strength or Strong Push to dam currents too swift to Surf across. The lowest level is the roost of the Legendary Pokémon Articuno, and Misty trains here as well. In Generations II and IV the caves also house the relocated Cinnabar Gym after a volcanic eruption destroys the original.