100 Rupees

Inside Cave east from the River Zora Village.

Use Bind to move the Wooden Box onto the button in the first two rooms. For the third room, ignore the boxes and Echo a Boulder etc. from a distance.

Inside Cave at far north-west corner of the Gerudo Desert, up on the highlands.

Behind iron bars in the third room. Look for a switch to deactivate the bars.

Reward for getting a fast time in the Acorn Gathering minigame at Zora River.