Secret Cave

In the Wind Waker, a Secret Cave is similar to  Ocarina of Time's Secret grotto. A secret cave is a cavern under the earth that can be acessed by falling into holes on the ground. There are a total of twenty secret caves in the Great Sea. Most secret caves are constructed in two standard forms.

Forms of Secret Caves
The first common form is a large, pillared, central room surrounded by four rooms full of enemies. Each time you complete a room by killing the enemies within, a candle is lit above its door. Light all four candles and you will have to fight a group of powerful enemies in the central room. This unlocks a back room containing a chest of some sort. This format is used for some Triforce Charts, and other assorted caves throughout the game.

The second common form is a large central room surrounded by three high perches from which enemies enter. Usually you will have to systematically defeat the enemies in order to make a chest appear in the center of the room. An exception is the secret cave on Angular Isles, where you have to build a tall block tower to reflect light.

Secret Caves are not limited to these two forms; numerous other unique caves exist. Notable examples include Outset Island's Savage Labyrinth, a 51 story deep monster melee, the two secret caves on Fire Mountain and Ice Ring, and Pawprint Isle's lush, winding, cavern filled with ChuChus.