The Fiendlord's Keep (also known as Magus' Castle in the SNES/PS version) is a location in Chrono Trigger that appears in 600 AD. It is Magus' castle and, according to legend, is home to 100 monsters. It is destroyed when Lavos awakens prematurely, causing the creation of a super-massive Gate that flings everyone through time and swallows the castle.