Dheub Gherno

From Rathe

An underground area of Rathe, which exists deep below the surface of the world. These areas can be large with cavernous ceilings and vast distances between cave walls. It is not uncommon to find a particular region with ceilings a mile high and walls almost 20 miles in diameter. These larger regions are connected through various tunnels, magma chambers, underground lakes, etc. Some of these regions have air, while others do not.

There is an entrance into a part of Dheub Gherna called Bulgoths Verna in Heildregch.