you go to fire island
beat the game and get to the indigo or orange or whatever islands, where u find hoenn pokemon.
It has 25 floors, the 25th being the treasure room.
If you don't get it from seafoam islands you must have a friend trade you one from there leafgreen or firered or get one from Pokemon xd gale of darkness.
The Sevii Islands are part of an optional sidequest that gives the player access to capturing pokemon that normally dont appear in the Kanto map, also completing the Ruby quest on One Island will let you access islands 4-7, lastly finishing the Sapphire quest on Six Island will grant you the ability to trade between the Hoenn Pokemon Games (Ruby, Sapphire, Emerald) along with Pokemon Colosseum and XD Gale of Darkness.
The Sea Foam Islands are not in Pokemon Ruby.
The Orange Islands do not exist in any Pokemon game.
The orange islands are made up islands strictly used for the Pokemon cartoon.
The Sevii Islands are a fictional archipelago of nine large islands and several small islands surrounding them. They are far south of Kanto, and are home to several legendary Pokemon. They appear in Pokemon LeafGreen and FireRed, and peripherally in Pokemon Emerald.
No legendary resides on the islands a rare Pokemon resides on seven island in the tanoby chambers the Pokemon is unown.
Explore, catch pokemon, train your pokemon.
On Seafoam Islands.
Yes, articuno is at the end of seafoam islands. Try the boulders ;-)