Bilmgar is a swamp bordering the southern edge of Ice Cap. It came into being a few months after the northern Temple of Begnhidrir received its first sacrifice.
After reducing our eldritch foe to ash, the fires of Eyfari came to life with enormous energy, releasing a wave of heat that soothed the throng of worshippers. This heat intensified when it tasted the ice of Glarvard. It quickly reduced them to bluish pools of water and then evaporated them. The heat of Eyfari's fires continued to expand outward with each sacrifice until, after about the 150th one, it had extended out to 20 miles. In this area around the temple, no ice or snow lasts long. Eyfari's fires quickly boil and evaporate the bluish magic tainted water of Glarvard, while leaving the normal water to drain away unaffected. All this melting of snow and ice drains towards the Rute as a newly formed river I shall call Skurd. The headwaters of Rute, unable to contain all the melting, overflowed its banks, creating a dreary swamp which I shall call Bilmgar. Let these two heroes be remembered by these areas, blessed be their names.
- Drokust, frost giant High Priest, from a tome in Hel's Church of Atlas, "The Fires of Eyfari"
Early in the Horgon Era, the Titan Empire of Saer Erkjorg warred with the people of Hel. In the Battle of Bilmgar, the eldritch giants scaled down the ice walls of Ice Cap and made their way towards Hel. The goliath met this army with nearly two dozen druids armed with a powerful ritual spell. The spell caused the land to buckle and opened up channels to a geothermal region far below the surface. This resulted in hundreds of geysers erupting and feeding enormous amounts of scalding water into the area. Furthermore, the heat and water entering what was becoming a geothermal fed swamp caused the nearby walls of Ice Cap to melt and add to an expanding wetland.
In the Second Battle of Bilmgar, the eldritch giants tried to avoid the geysers and the goliath's acid rain spells by using Lith-Crillion magic. They used the spell Create Living Vault, to make 38 living vaults, sized for giants, and able to traverse rugged and muddy ground on specially made footpads. The giants made swamp crossings several times with dozens of living vaults, but with each crossing the ground became more muddy, and one by one the living vaults became mired in the swamp. Saer Erkjorg's army, led by General Heirmek, made it to the walls of Hel but lacked the needed numbers to take the place. They retreated from the area, pursued by the goliath for months. This would be the last army of Saer Erkjorg to consider attacking Hel. They never made it out of Esto'khar, reduced daily by goliath guerilla attacks and others seeking to take advantage of another's misery.
The earth giants of Vigring, once friends before becoming a vassal state to Saer Erkjorg, saw weakness in their masters, and took every opportunity to bloody them during Heirmek's Retreat.
- Gizdalur, goliath battle chronicler, from a Chronicle Column in Hel - "Second Battle of Bilmgar"
Bilmgar is littered with living vaults. Most of these constructs are still intact, though buried deeply in mud or partially submerged in hot water. Since they were lost so long ago, some intrepid souls have tried to get a living vault out of the swamp. Only one has succeeded in this difficult task, with the others failing to unlock the magical attunement on the devices.
Steaming water, scalding geysers and noxious gases make Bilmgar a deadly place to travel. Only those creatures accustomed to high heat, make their home here. This includes steam mephits, mud slaadi, scalding water spitting lizards, bog giants, and other dangerous foes.