Kur is a region deep underground within the Darklands. Lying far beneath the surface nation of Ishtar, Ker a truly massive cavern, hundreds of miles in width and length.
The Sea of Irkalla sits in the middle of Kur, its pitch black waters home to any number of monstrous creatures of the depths. The shoreline around the sea is relatively narrow, only a few dozen miles in most places and hotly contested by the various inhabitants of Kur. Archipelagos of small islands, some natural and some artificial, dot the sea. The Kirak River that begins in the Zagros Range provides fresh water from the surface to the sea, as do a number of smaller rivers that flow underground through cave systems. Sightless creatures, including bony fish, giant squids, and others, dwell within the sea - despite the rough conditions in Kur for those that cannot reside in the water, the inky depths are teeming with life. Most of these creatures, however, are best avoided.
Unlike most of the deep caverns of the Darklands, Kur is almost barren, with those that reside there forced to fight over dust and scraps. This does not make Kur any less dangerous than the other deep caverns, however; if anything, it only makes it worse. The islands within Irkalla are refuges from the danger, home to small communities of munavri, caligni, and fetchlings. Around the sea live xulgaths, deros, urdefhans, morlocks, and others, who constantly attempt to expand their territory and subjugate their neighbors.
Naturally-occurring portals to the Abyss frequently open in Kur, which allow demons to pour forth into the cavern. The arrival of these demons is the only factor that can influence the inhabitants of Kur to put aside their differences and cease fighting, at least for a time. Some inhabitants of Kur have taken to worshiping Lamashtu.
There is no large-scale artificial lighting in Kur, though some communities have taken to burning the pitch that seeps from the walls for illumination.
Spread around Ishtar are seven entrances to Kur, leading directly from the surface to the cavern. The largest of these is a staircase large enough for a dragon to comfortably fly within, located under Birtuamurru. The fortress attempts to monitor and guard the entrance as well as possible.