The Moaning Lands of the Dead and Dying. Many foul creatures of undeath roam here and seek living flesh, no one is quite sure what happened to this large desert island. Maybe you could unlock the mystery and free the tormented.
Pirates' many bejeweled rings and piercings actually had a practical purpose - when the pirate or sailor died, the rings could be taken off as payment for a proper burial, saving him from a watery grave. This could be tied into regional culture, or made into a quest (The Pirate's Lost Rings, etc.). Also gives treasure-seeking divers another thing to look for besides crusty old chests.