|Hlothram Defense Network, HBR
During the Horgon Era, the Zeymah'kein Empire sought to expand their territory into Trudnar's resource rich peaks. In the southeastern flanks of this volcanic mountain range, the Imrithil encountered a stiff resistance from hobgoblin forces out of Garâtha. When the Kriistvrii army was within sight of Valefor, hobgoblin wizards opened up a gate to the Abyss. An army of demons stormed out and laid waste to the attacking army. The Imrithil were routed, and instead of being on the offensive they were forced to go on a prolonged defense that lasted almost twenty years. During this time, they built up a massive series of fortifications and walls along the western slopes of Hlothram. These fortifications became known as Hlothram Bildrun Rigevoth ("Hlothram Defense Network").
Hlothram Bildrun Rigevoth, or HBR, is comprised of forts, towers, and walls spread across a fifty mile line where Hlothram meets the Dargirth. The fortifications are expertly engineered and built to guard against ground, air, and sub-surface attacks. They also have unusual features to combat things of huge size and to deal with area of effect attacks. The structures are made of basalt, obsidian, and lava stone.
When the demons of Garâtha mysteriously disappeared, Zeymah'kein decided that the cost of maintaining and garrisoning the vast fortifications was too much. Hlothram Bildrun Rigevoth was abandoned to the wild. Today, the fortifications of the area are still mostly intact. They are abodes of bandits, monsters, and other creatures. Some of the areas have been damaged by floods or been submerged by changing flow of the Dargirth.