The mural on the door to the Pillars of Light say that the "holy metal of magnesia" is the key to the underworld. After turning the ankh in the statue's hand, the statue moves, showing the players "the underworld" (the reception room). This is the deepest room in the cavern, and, as its name suggests, this where, it is presumed, receptions for weddings, parties and other such things were held.