Caer y Seren, corrupted as Kaer y Seren or Kaer Seren, was a seat of the witcher School of the Griffin. Built at the sea end of a mountain range in Kovir and Poviss it used to possess a great library. The very library which caused the downfall of the keep after a group of mages caused an avallanche to punish the witchers for not sharing their knowledge. Many inhabitants died and the keep was badly damaged.
- Contrary to Szpony i kły and The Witcher Role-Playing Game, the Wiedźmin: Gra Wyobraźni locates the Gryphon keep in the Amell Mountains. This was probably changed because Amell is already a seat of School of the Bear in CD Projekt's The Witcher franchise.