Weak Wall

Breakable Walls reoccur through The Legend of Zelda series. They are simply walls that can be broken with a Bomb. A common feature of these walls are cracks in them. When Link hits a breakable wall with his sword, they make a special sound.

The Legend of Zelda: Spirit Tracks
In the back of Hyrule Castle, in which a guard instructs Link that there use to be a cave somewhere around there.