Black Forest

The Black Forest, a putrid woodland that claims for itself even more space than the Varlem Desert, is a place of unambiguous evil. It is at the center of this dead place the Heart of Hate, the crystallized heart of the Progenitor and now the prison of the Adversary, resides.
  From the Adversary's disturbed dreaming, abominable nightmares spill forth from the heart like pus from a weeping wound. Nothing except monsters live in the deepest, central parts of the Black Forest and the total silence of its dreadful depths is only broken when the Hatelings crawling in the rotted undergrowth either devour eachother or some unfortunate soul that has somehow ended up in the cursed woods. The vast majority of the forest is bathed in the ominous red sheen of the Heart's hateful radiance.
 

Geography

Being so massive, the Black Forest has actually formed several different ”biomes”, if its mockery of nature can be called such. These biomes are the Death's Head Orchard, Gutmire, Demented Glen and the surroundings of the Heart of Hate itself.
  Each of these locations are dangerous beyond reason, with the threat compounding the further one travels into the forest proper. Without a knowledgeable guide, armed escort or supreme survival skills, traversing the Black Forest is a death sentence or worse.  

History

In the distant past, before the Progenitor fell onto Nascindor, the Black Forest was known as the Great Forest. It was a wild, overgrown place full of verdant life that served as the home for several ancient tribes of men. When the dying god crashed into the forest, the impact created a crater that the Progenitor eventually died in, but not before delivering its message to the primitive humans. Over time, the god-corpse withered away, leaving behind only the crystallized heart that the Adversary remains imprisoned in to this day.