Yeenoghu's Realm

The savage demon lord Yeenoghu, Prince of Gnolls, rules the dun savannahs of the 422nd layer of the Abyss, which he unimaginatively calls "Yeenoghu's Realm." The name fits, for the countless gnolls and mortal slaves who dwell under its low-hanging red sun consider Yeenoghu the unquestioned leader of all he surveys from the ledges of his towering mansion. The edifice, as large as a human city, rests upon great stone rollers, allowing it to be pulled throughout the layer by thousands of slaves kidnapped from the Material Plane.

Roughly every year, the palace makes a great widdershins circuit of the realm's three primary encampment sites, stopping at the immense dormant form of the obyrith lord Bechard for Yeenoghu to gain telepathic council, and at the Gathering Gate to replace those slaves who have died under the strain of pulling the layer's capital.