Desert's Mouth in the Osirian Desert, near the Thuvian border, is a black pit at the bottom of a conical hole in the shifting sand dunes. It resembles the lair of a giant ant lion and its circular hole is a strangely regular entrance into a huge cavern which is probably connected to the Darklands. Phosphorescent gases drift out of the pit at night and those who stay too near the pit report hallucinations about dark caves dripping with water. Descending the sandy slopes is difficult but ascending is almost impossible. The Desert's Mouth hasn't been explored in recent memory but ancient texts describe forests of glowing fungus and strange crustaceans skittering in the dark.
The Yerbira are said to use the Mouth to execute those who breach their few taboos. They lower the condemned into the pit with a rope and throw the rope after him. If the condemned can climb out the pit he is considered forgiven. No one has ever climbed out the pit so far.