Fullmoon Island

Once the player has both entered the Hall of Fame and obtained the National Pokédex, the son of Sailor Eldritch, who runs the ferry to Iron Island from Canalave City, falls into a sleep from which he cannot be awoken and is plagued by nightmares. To cure his son, the sailor begs the player to take the ferry to Fullmoon Island to get a Lunar Feather. Upon arrival, the player will find that there is not much to the island besides an entrance to a deeper area of the island, where Cresselia waits. After encountering her, she will fly off and begin to roam the routes of Sinnoh. As soon as Cresselia has left, the Lunar Feather can be found where she was.