Dark World

On the east side of the pyramid in the Dark World.
One of the chests in the chest game in the Village of Outcasts (Hook Shot).
Hammer all the stakes in the area east of the Village of Outcasts where smithy's shop is in the light world (Titan's Mitt).
In a cave in the Swamp of Evil (Flute).
Go through a cave east of Skeleton Forest. Use the Magic Cape to get past the rebounder. (Magic Cape)
Play the treasure digging game south of the Village of Outcasts. You may have to play the game several times before you find it. (Hammer)