Scattered all over the overworld. There are several Vaults constructed by the thief Blind ages ago. They are identifiable on the outside by an emblem carved by their entrance, but are otherwise hidden. Inside each is a mini-dungeon. You must find a key in the dungeon, which will open the vault room, located at the dungeon's heart. Inside the Vault are treasure chests containing ruppees, and a switch. Activating the switch will teleport you outside the vault, and the emblem outside will glow blue.
Long ago there was a mystical band of thieves, led by the most vicious, cutthroat thief of his day: Blind. They robbed every soul they encountered, down to their last ruppee. They seemed unstoppable. In the few instances when they were cornered, they disappeared in a flash of smoke, taking the loot with them. But as fast as their reign of terror began, it ended. No one ever knew who they were or where they came from. But it is said that whoever can discover Blind's vaults, their power as well as the treasure would belong to him.