Built in the swamp, not far to the southeast of Port Breigh, Tinesia Umelee built Helheim after being expelled from the Wood Elves for experiments on Humans. After her unsuccessful attempts created insane, but magically powerful witches she realized she would need to put a part of her Elven Life Essence into the formula, and it worked. After creating five high humans successfully, Tinesia died leaving Helheim to her children. Living high above the witches for a time, eventually the high humans realized they needed to move on, because mortals were growing increasingly fearful of them. Four of the first born left to form their own city, high in the mountains, leaving only Rubedo to look after and care for the witches, in their growing insanity.
During a battle between the Army of Port Breigh and the witches of Helheim, Rubedo single handedly turned the tide. Slaying hundreds of the human army alone, he forced their retreat, but later died from his wounds. Helheim was protected for many generations based just on the stories and fear of this unbeatable force, who lived high above. The witches grew more and more insane over the decades and eventually dispersed all over the land, choosing to live in isolation, rather than together, always on the lookout for a human to kill with their unparalleled alchemy.
Helheim sat vacant for years, the mutated netherwart growing all over the land, until more recently the Order of Man has made it's home there. After discovering Helheim was the site of the first successful High Human experiment, they have taken up residence in the city and are fighting every day to cut back the netherwart that has grown all over the city.