Diamond Steppe Island

Diamond Steppe Island is a diamond-shaped island in The Wind Waker. At a certain angle, it looks somewhat like a ship itself. Link must use the Hookshot to get to the top of it and enter a maze with many Warp Jars. The reward there is the Ghost Ship Chart, which marks the island appearances of the Ghost Ship on certain moon phases. After obtaining the Ghost Ship Chart, at night a glowing ship symbol will appear also on the Sea Chart. Coincidentally, the island itself is one of the seven recurring destinations of the Ghost Ship.

There is also one eight-eyed Big Octo which Link can destroy for 100 Rupees. In addition, beneath the waves is a chest with a Heart Piece that can be located after opening a Treasure Chart from Windfall Island.

Trivia

 * The layout of the island's underground maze is similar to the grotto found on Needle Rock Isle.