Castle Mairwyn was a massive, old-fashioned central keep, located near Serabor in the Barony of Larchros, in the Princedom of Corisande.

By the Year of God 894, it was well over three centuries old, and despite the enlarged, many-paned windows which had replaced most of its upper firing slits, the old fortress looked its age. It was the site of the Serabor Raid, where the Baron was arrested and the Northern Conspiracy was shut down. (AMF)