Forest of Teeth
The Forest of Teeth is one of the nightmare dreamworlds that the onirarchs of Dadauar have created to punish the rebellious and recalcitrant. The "teeth" in the forest's name refers not to the trees of the forest, which are leafy and ordinary, similar to the trees found on Dadauar, but to the forest's inhabitants. The Forest of Teeth is full of vicious—and toothy—beasts of various sorts, few of which need much provocation to attack passing dreamers, tearing them to shreds with their deadly dentition.
A dreamer slain by the creatures of the Forest of Teeth is not physically harmed in the waking world; his body back on Dadauar is free of the wounds inflicted on his dreamself. It's still extremely painful and unpleasant, though, of course, and when his dreamself dies the dreamer will awaken. If he's been redirected to the Forest of Teeth, however, he's just going to end up there again in his dreams the next time he falls asleep, only to go through the whole process over again. Someone whose dreams take him to the Forest of Teeth is likely to get very little sleep, and not be well rested from what little sleep he does get, and to be in the waking world constantly on edge and tired and jumpy.
Dream redirection to the Forest of Teeth is therefore a punishment the onirarchs reserve for particularly bad offenders—for milder cases there are plenty of other unpleasant dreamworlds they can direct them to that aren't likely to have quite such extreme consequences. In particular, given how much it, in the long run, limits their effectiveness in the waking world, the onirarchs favor redirecting to the Forest of Teeth people whose activities actively hampered their operations or plans—uncondoned smugglers and black marketeers, known spies and agents of other onirarchies, and other troublemakers of various sorts.
Formerly, many resistance members were redirected to the Forest of Teeth, but this is not done as often now since some resistance cells have actually managed to set up outposts in that nightmare world, manning them in shifts. Defended against the monsters that roam the Forest, these outposts serve not only as resistance bases in Goetogenia where the resistance can meet without the onirarchs' oversight, but also occasionally as recruitment centers; resistance members in the Forest can rescue from the slavering beasts some of those sentenced to dream redirection there, bringing them back to the outposts and indoctrinating them in their ways of rebellion against the onirarchs. Only a few resistance cells have so far managed to create these outposts, but their existence has still discouraged onirarchs from sending there rebels not associated with those cells (though it hasn't stopped the practice entirely), for fear other cells might follow their lead.
Although the onirarchs usually claim to have created the Forest of Teeth, there is scant evidence of this, and most serious scholars as well as resistance members believe that some onirarch or his agent simply found the site while exploring Goetogenia and decided it was sufficiently terrible to serve as a place of punishment. It's not certain how big the Forest is, or whether it forms a self-contained plane—if anyone has managed to leave it and discover what lies beyond its borders, they haven't returned to tell the tale.