There is a chain of high mountains wherein, should a traveller climb them, they may suddenly come upon a valley.
This valley resembles the hells that various religions speak of - a place of fire, plague and torment.
Although the damned souls here appear human, those who have tried to talk to them report that they speak no known language.
One traveller reported fashioning a mask to survive the sulphurous air of the valley, and infiltrating it in the guise of a devil. He communicated with some of the damned through sign language, and arranged to help them escape. But as soon as they left the valley and breathed clear air, the damned began to thrash around as if they were drowning. After a minute or so they were dead.