The Cave of Sadness was a cave that was sorce of Sadness. A young princess named Cassie, who about fourteen years old, put the Cosmic Crystals in this cave. So her rival, Master, should never destory her world, the Star World. Years later, a man named Mario discoverd the cave and found the crystals. Mario came to the Star World and destoryed Master. everyone was prond, even Cassie. Cassie rewarded him, But keeped the crystals. it is unknown what happend to the Cave of Sadness.