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.
Another real world thing. White tea. Can only be picked two days a year, the two days before the flowers blossom. Could be a similiar plant that...is the deadliest poison known, cure known diseases or psychosis, or a potent herb that just tastes awesome.