Pokémon Gold and Silver/Whirl Islands

Pokémon Silver
After beating Team Rocket at the Radio Tower in Silver, the Director will thank you by giving you the Silver Wing which allows you to catch Lugia in the Whirl Islands. You'll need the HM03(Surf), HM05(Flash) and HM06(Whirlpool) to get through the islands which are between Olivine and Cianwood City.

Enter the cave that is located at the upper right. Go up and right and take the stairs. Go down and turn left, take the stairs. Surf and go down the waterfall, you'll find Lugia's cave. For getting out just exit the cave, surf and you'll find stairs, you'll leave an inner cave. Take the stairs which go up and you'll exit one of the Whirl Islands. Lugia's moves are: Aeroblast, Safeguard, Gust and Recover. Ultraballs and Pokémon capable of sleeping/paralyzing will be useful to catch it.

Pokémon Gold and Crystal
In Crystal you receive the Silver Wing from the man next to the Pewter City Poké Mart after defeating the Elite Four. The procedure to reach Lugia is the same as Pokémon Silver.

Pokémon found

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* Only one of each.

Items

 * Guard Spec
 * Ultra Ball
 * Escape Rope
 * Calcium
 * Carbos
 * Max Elixir
 * Full Restore
 * Nugget
 * Ultra Ball
 * Max Revive
 * Max Ether (Hidden outside on the southwest Island, in the northwestern corner on the ground.)
 * Ultra Ball (Hidden inside in the main cave area, on the east side at the end of a short dead-end path)
 * Full Restore (Hidden inside in the main cave area, on the west side in a rock, which is surrounded by wall on two sides.)