Watchtower Key
From Golden Sun Universe
The Watchtower Key is an important Item in Golden Sun: Dark Dawn. The key is given to Matthew's party by Ikan the storyteller after the party rescues his son and grandson. Ikan had apparently kept the key for some time while waiting for an ancient prophecy to be fulfilled.
The Watchtower Key unlocks a secret chamber in the central watchtower of Warrior's Hill, allowing the player to collect the Watchtower's treasure, the Third Eye.