Good Magicians Castle

From Xanth

The Good Magician's Castle is on the same site as Castle Zombie was during Roogna's life time. It is, as the name suggests, the residence of the Good Magician Humfrey. To gain entrance one must overcome three challenges, set up so that only those that are serious will be able to get in and have they're question answered. Then the Good Magician Humfrey answers they're question in exchange for one year working or equal service.