Uncharted Island

Uncharted Island is an island found in The Legend of Zelda: Phantom Hourglass.

Located close to the Isle of Gust is an island without a map. This is simply referred to as Uncharted Island. However, once charted, the island resembles a spouting whale. This may be a reference to Oshus, whose true form resembles a white whale.

When you solve a riddle that a statue out front of a cave gives you ("It steers with rudder, then makes spray, moves with paddle then sees a way"), you can enter the cave in which dwells Cylos, the Chief of Golden Frogs. He reveals that he is friends with Oshus and gives Link the Cyclone Slate to help Link save him.