North and east of Blizrynthine, the Hills of Insanity roll across northeastern Pherezi Imnuttut. The name is not metaphorical. Something about this region affects the mind—travelers report auditory hallucinations, paranoid ideation, and in severe cases, complete psychotic breaks. The effect worsens the longer one stays and doesn't fully fade for weeks after leaving.
Scholars have proposed various explanations: a curse from the early ages, contamination from the nearby Thermarifts, proximity to some buried entity, or simply the cumulative psychological toll of the Northern Isles finally manifesting. None have been proven. The hills remain largely unexplored, as expeditions tend to turn on themselves before accomplishing anything.