Hollow Heart

Notable Locations:
Athawyn:
The most debased and decadent city in Hollow's Heart after Zoragmelok itself, Athawyn was a dizzying tangle of curving towers and massive domes all made of red stone. It was inhabited by approximately 9,000 fiendish orcs and half-orcs, served by numerous human slaves deemed unfit for the Red Rapture. Succubi and skurchurs served as the lords of the city, which Nyrashlia, a powerful succubus bard, ruled. Athawyn was the only city in Hollow's Heart not ruled by a Hollow Rajah, but the chaotic rakshasas did not seem to resent this and often visited the city to indulge in its more carnal offerings.

Blood Dunes:
A vast desert of sticky, blood-red particles that never dipped below temperatures of severe heat, and often rose to temperatures of extreme heat. "Ruins" covered in "sand" lay deep within its expanse, and were crawling with powerful mummies and liches. Close inspection revealed the "sand" to actually be scabs and clots of dried blood.

Bonepus:
Perhaps the most wretched town in Hollow's Heart, Bonepus was a settlement of some 1,560 fiendish goblins ruled by the crocodile-headed Hollow Rajah Rontakus, who devoured his subjects frequently enough that the goblins' fecundity could barely keep up with his appetite. The buildings of the soggy, dripping town were made of rotting wood and poorly preserved strips of skin and leather stretched over frames of twisted sticks, harvested from the nearby Scarwood.

Deathroot Woods:
A forest of twisted, diseased trees, primarily Abyssal varieties of oak and pine, that sprawled across the lowlands and foothills of the Demon's Teeth. The forest floor appeared to be covered by countless bones, which were actually the roots of the trees. Tainted plant monsters dwelled in the woods, and rumour held that the place was ruled by a circle of thirteen half-fiend treants.

The Demon's Teeth:
One of the first regions made by Fraz-Urb'luu after he returned from his imprisonment, the Demon's Teeth was an immense mountain range full of rock faces and ledges sharp enough to lacerate and cripple unwary climbers. Four deep lakes full of bile lay within the range, held by the few enemies of the demon prince that he could not drive away.

The Drooling Jungle:
A massive jungle of fleshy trees that drooled caustic bile and poisonous ichor from gaping mouths, with strangely pliant trunks and swollen greenery. The ground was a warm, rubbery sheet of flesh covered with thick black hairs that doubled as undergrowth. It was primarily inhabited by basilisks, hydras, and numerous barlguras, as well as a gigantic nalfeshnee known as the Gardener, which protected the jungle.

The Flensers:
A jagged range of volcanoes surrounded by strangely angled mountains that resembled razor blades. The volcanoes threw lava and ash into the skies above.

The Forever Gash:
A long strip of land running through the Demon's Teeth, it was composed of the white powder that once formed Hollow's Heart. For reasons unknown, it resisted Fraz-Urb'luu's efforts to reshape it, and so it remained a strange incongruity in his twisted realm.

Harrowfen:
A poisonous, murky swamp that lay along the southern shores of the Hollow Sea. Only creatures immune to poison could live there; naturally, demons, particularly hezrous and skulvyns, thrived there.

The Hollow Sea:
Most of the layer's civilisation was located on the shores of this inland ocean, full of poisonous water, too green to be natural. The many small islands in the sea were rife with temporary portals to various Material Plane worlds, and unfortunate travellers and explorers often stumbled through and became trapped. The waters themselves were infested by half-fiend sharks and worse horrors, including at least one myrmyxicus demon. The Hollow Sea was effectively bottomless: a determined swimmer could theoretically swim all the way down to the 177th layer of the Abyss.

Karantis:
Built on a mesa overlooking the Hollow Sea, this city-sized temple of iron and porphyry was the heart of Fraz-Urb'luu's cult. The Hollow Rajah Kiltikairit ruled it.

Karugoza:
A small city inhabited by about 7,500 orcs, ogres, and fiendish gnomes, ruled by the Hollow Rajah Liorkian. The city's primary purpose was to process the many humans captured by Fraz-Urb'luu's servants. These humans were either captured from islands in the Hollow Sea or, more often, were kidnapped off of various Material Plane worlds by demons or cultists. A healthy human sold for about 100 gp in its markets, while sickly humans were sold at significantly reduced prices, and often wound up as slaves or food in Athawyn.

Magghat:
A large town with a population of about 3,200 orcs and ogres, most of whom were sailors who spent weeks sailing the Hollow Sea in search of slaves on the islands there. It was ruled by the Hollow Rajah Zurathani, who used his artistic interests to create horrific statues for the city streets.

The Red Rapture:
A vast stretch of plains just north of the Blood Dunes, the ground itself here was a reeking morass of bloody mud, and all kinds of torture devices could be found scattered around. The Red Rapture served as a single massive killing ground for most of the humans captured by Fraz-Urb'luu's minions. Vrocks were the primary inhabitants, acting as torturers and executioners.

The Scarwood:
A deciduous forest inhabited mainly by the scar-covered survivors of Zoragmelok's walls and strangely free of most dangerous predators and demons. The woods served Fraz-Urb'luu as a personal hunting ground, where he allowed the humans to live long enough to form primitive societies of scavengers, waiting long enough for them to gain a sense of hope, before either ordering his demonic servitors to hunt them down or doing so himself.

The Spiral of Ugudenk:
One of the few enemy strongholds that Fraz-Urb'luu could not oust, this region of the layer had been claimed by Ugudenk and infested with its writhing minions. A vast, spiralling cavern at the centre of this layer led all the way down to the 177th layer, which was Ugudenk's realm. Fraz-Urb'luu had tried three times to destroy the caverns but had failed each time; since Ugudenk seemed content to lurk only in this region, Fraz-Urb'luu suffered from its presence. Other demon lords jokingly referred to this situation as Fraz-Urb'luu's "infestation problem".

Uanthur:
The sister city of Magghat, Uanthur, was inhabited by about 3,000 orcs and ogres with similar occupations of sailing and slaving. The Hollow Rajah Proaliak ruled it.

Zoragmelok:
The mightiest city in Hollow's Heart, Zoragmelok, was the personal fortress and lair of Fraz-Urb'luu himself, but was only inhabited by his succubi consorts and the souls of many deceived petitioners.

Shullen-Gat:
Not a location within Hollow's Heart, this iron fortress was located over a pit on the Plain of Infinite Portals that led to Hollow's Heart. A minor demon lord claimed it, and a former Blood War general named Baltazo, during Fraz-Urb'luu's imprisonment, who used his control over access to the layer to subtly influence events there. After the demon prince returned from his exile, he saw the value in having a strong defence at the portal, and agreed with Baltazo, who became one of Fraz-Urb'luu's vassals.

Fraz-Urb'luu was one of the first tanar'ri demon lords to dominate a layer of the Abyss, rising to power in the last days of the obyrith dominion. With the aid of his staff of power, he could raise mountain ranges or drain entire oceans on the layer with but a thought. His mastery over Hollow's Heart meant that his many foes were unable to defeat him.

At one point, the demon prince Demogorgon invaded and seized fully half of Hollow's Heart, and would have taken the other half had he not been forced to return home by the demon lord Zuregurex's attack on the Gaping Maw.

However, Fraz-Urb'luu's arrogance and habit of humiliating his fellow demon princes eventually led to his downfall, when his erstwhile foes helped a mortal wizard imprison him on the Material Plane for more than 200 years. During the time of Fraz-Urb'luu's imprisonment, demons fought over his layer, destabilising it. A few managed to carve out islands of their own, but the majority of the layer was ruined.

When Fraz-Urb'luu finally regained his freedom and returned, he found his beloved layer to be little more than endless white powder under an equally empty sky. After driving out the majority of the squatters who had made islands in his absence, he began rebuilding the layer, although without the staff of power, it was slow going, and by the late 1480s, much of it remained white powder.