The Sorcerer of the Blue Mask has designed the four main structures of his fortress to each feature one of his hobbies.
- The Citrine Hall, home to craftsmen who construct musical instruments designed in dreams.
- The Rosy Chambers, devoted to the exploration of the uttermost limits of the pleasures of the senses and the flesh.
- The Verdant Scriptorium, a prison for a score of faceless monks who spend their days translating the Bible into languages that do not exist.
- The Azure Tower, where alchemical formulae are derived by tracing new constellations in the night sky.
Each of these four locales has an entrance to the underworlds below the castle, known collectively as the Vaults of Vyzor. The Sorcerer of the Blue Mask has invited the brave and foolhardy of the realm to enter the Vaults, if they dare. Little is known about the dungeons below, save for these well-known clues:
- The Orcs of the Red Hand have their headquarters somewhere below the Citrine Hall.
- The tunnels below the Rosy Chambers are said to be haunted by the restless dead.
- The howling of wolves can sometimes be heard coming from the dungeons below the Verdant Scriptorium.
- The dungeons below the Azure Tower are said to be part of the domain of the Unseelie Court.
One other important item: Use of the entrance in the Azure Tower is by invitation only. The Sorcerer of the Blue Mask only permits those he deems worthy to enter the tower.