The Mirror of Nightmares is a portal to the Realm of Chaos located in Araby.[1a]
One legend says that around 1460 IC, while crusading in Araby Marius Hollseher, the Elector Count of Stirland, discovered the Mirror of Nightmares and inadvertently traveled through it into the Realm of Chaos. For reasons known only to the Chaos Gods, the Count was allowed to return to the mortal world unharmed, where he wrote an account of his journey in the Liber Malefic (shortly before being burned at the stake).[1b]