Once the crown jewel of the Dwarven Empire, this massive and sprawling underground region may as well be another world. It stretches far beyond the The God's Teeth Mountains, beneath the The Ephemeral Sea, into the Gaul Do Shah Caverns , and all the way down to the The Ramaal Jayiea Desert . Before the Blight, the Kingdom of Underhome was larger than any other, having made it's mark on Cairne far earlier than most other species with wondrous works of architecture and design, working the stone and rock beneath the surface of Cairne for centuries as they developed myriad methods of manipulating their environment. From the deep reaches of their domain, the Dwarves pulled mineral riches and buried secrets that rival many stories of legend, but all of that came to an end the day the Blight fell, leaving the majority of the once shining kingdom a bone strewn ruin filled with the black power of the Void and crawling with horrors the surface dweller dare only imagine. While the remaining Fouvienians fight day and night to hold back the unhallowed hordes of shadow and bone, their history is slowly being lost to time and ravages of a war that never ends.
Winding tunnels and caverns that stretch on for hundreds and hundreds of miles, and nearly all of it filled with an oppressive darkness that allows the beings of the Void the flourish and prosper unseen. The stone of Underhome has as many variances as the forests of the Gaul Do Shah once had trees, but in a not dissimilar fashion, nearly all of it has been lost to the Void, and what the Void claims is never the same again. The cavernous reaches lay beneath the majority of the Eastern Wastes, though only a tiny fraction beneath the God's Teeth mountains remain inhabited by the Dwarves themselves.
The remains of the Dwarven kingdom is a barren and desolate place, but as the Void has settled there, a violent and unforgiving order of life has emerged. Mutations and even new forms of life and undeath have sprung up from the stone and the remains of the fallen kingdom that show a remarkable resilience to many of the known and standard means of surviving such things elsewhere. Fungal outcropping that have not only survived but absorbed and mutated due to the energy there are now voracious carnivorous plant life, while the insect population has adapted to the scarcity of scavengable food, many of them now locked into a symbiosis with the undead that crowd many locations. Not all of the life that remains in the region are so wicked, however, as some common animals, such as the Messenger Bat have changed in a way that has benefitted the living inhabitants.