Uncharted Island

The Uncharted Island is an island found in, and is located in the eastern side of the northwestern quadrant of the sea.

Features
The island is located to the northeast of the Isle of Gust and is the only island without a pre-existing map. Therefore, it is simply referred to as Uncharted Island. However, once charted, the island resembles a spouting whale.

There's a cave on the island that can only be accessed if Link first solves a riddle: "It steers with rudder, then makes spray! And third, it paddles, then sees a way!" Taking the shape of the island into account (that of a whale), Link has to hit four Gossip Stones in the order the riddle indicates. After that, Link can enter the cave in which dwells Cylos, the leader of the Golden Frogs. He reveals that he is friends with Oshus and gives Link the Cyclone Slate to help Link save him.