Shademurk

Fenthras resided here, at it's very heart.
The Shademurk, as far as I understand, was once a very beautiful landscape. That once was the fountain heart of the Gilded Run that provided the flowing rivers that spun throughout this entire region. There was an archfey ( Saundor ) many years before who was turned on by his beloved, who had been growing so spiteful, so full of angst and anger and vengeful thoughts that it turned his heart dark and black and he began to spill into the fen around him.
It was there that these lands became the Shademurk. It was there that he became one with the land and corrupted it and turned it. Dryads turned foul and shadowed. Other creatures began to crawl up from the bog itself, and to this day feed off the life of those they can reach.
The only thing that holds its spread at bay is the Gilded Run, the rapids. Now, it's found balance, and we watched it spread, as those who've lived here for a long time do. It does not force any sort of immediate threat to any of us, and it serves its own purpose. It has its new-- I shouldn't say new, it's been hundreds of years now-- but its own life, its own biome.