|Type||Tier 1 Underdark|
The Underdark region beneath the surface of Grashakh is called Imgangreth. The area under Grashakh has a deeper Underdark than other areas of Brucrumus. This is attributed to the higher elevations of the central landmass of Brucrumus.
Imgangreth is filled with vast expanses of fungi forests, or fungals, and countless waterways. Some of these same waterways feed into the surface regions above. The largest of these is the Umgaril. The largest water body of Imgangreth is Cthorgo.
Some of the plant life in this Underdark realm is mammoth in size with 30' diameter mushroom caps and spore fields covering thousands of yards to name just a few.