 Additional information about the Maure Castle dungeon levels is also revealed in James Jacobs' "Demonomicon of Iggwilv" article on Malcanthet in Dragon #353 (Elluvia's Pit is specifically mentioned).There are at least 8 portals to other planes as "Expedition To The Ruins of Greyhawk" states that the apprentices of the last Suel mage of power, Slerotin, left Oerth at Maure castle, each to their own personal demiplane.The key to access one world is a magical device called an Octych.