Third Treasure of Rule
The Third Treasure of Rule was one of the Thirteen Treasures of Rule, bestowed upon Teron by Primus when they were attacked by Bloth in the Sea Fields of Aymara. Teron took it to his home in Andorus, where he hid it deep underground before his own capture and imprisonment by Bloth. But before he was taken Teron placed a spell on the treasure, so that only a member of the House of Primus, by themselves, could find it. As a result, this was the only treasure that the compass would not point to. It was also guarded (unwittingly, anyway) by the evil being known as the Blight.
Video Games
In the Super NES game of Pirates of Dark Water, although the Third Treasure of Rule is found also on Andorus, it is won not by fighting the Blight, but the Lugg Brothers.