Fullmoon Island

Fullmoon Island (Japanese: まんげつじま Full Moon Island) is an island located north of Sinnoh, where the Legendary Pokémon is initially encountered. Players may obtain the Lunar Wing in this place.

Geography
Fullmoon Island is a small island largely covered in forest. A short path cuts through the forest, and leads to a shaded clearing with a pond shaped like a crescent moon. Unlike most other locations in the Pokémon world, there is no tall grass here, and wild Pokémon cannot be found, with the exception of. She awaits the player in the middle of the clearing.

This island can be visited only after the undefined has become the and obtained the National Pokédex. It parallels Newmoon Island, an adjacent island that is the only known location of.

Event description
Once the player becomes the of the Sinnoh League and obtains 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 awaken and is plagued by. To cure his son, the sailor begs the player to take the ferry to Fullmoon Island to get a Lunar Wing.

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 waits. After encountering her, she will fly off and begin to roam the routes of Sinnoh. As soon as has left, the Lunar Wing can be found where she was.

Later in the game, this island can be revisited at any time, though the only reason to do so is because the northwest section of the Underground can only be reached from here or Newmoon Island.

In the anime
Fullmoon Island appeared in Sleepless in Pre-Battle!. and visited the island to find  and obtain her help in stopping 's attack on Canalave City.

In the Pokémon Adventures manga
In The Final Dimensional Duel V, told  how he had visited Fullmoon Island in search for a Lunar Wing to cure Eldritch's son Vijay several weeks prior. When he had arrived at the island, he had found numerous wild Pokémon asleep and having terrible nightmares. All of his attempts to help the suffering Pokémon had proven futile, until suddenly had appeared above the island and used, ending the Pokémon's slumber. In addition, Cresselia had dropped down a Lunar Wing, allowing Eldritch's son to be cured, while Cresselia herself had chosen to join Palmer's team.

Trivia

 * Fullmoon Island is the northwesternmost area of Sinnoh.
 * When the son of Sailor Eldritch is having his nightmare, he says "Dar... Dark... Is watching me..." He presumably means.
 * Fullmoon Island's image on the Town Map is a mirror image of Newmoon Island.