Since it was mentioned, here's Erebus, the modern replacement for Pandemonium.
Endless Sewers of Erebus
It is the realm of infinite sludge-filled tunnels and rusty pipelines
It is where all things discarded eventually end up
It is the ultimate destination of the river Styx
Erebus is, by far, a sanitation worker’s worst nightmare. Old rusty pipes and labyrinth-like concrete tunnels stretch into mind bogglingly complex configurations only to disappear in the impenetrable blackness that surrounds all light sources. The first thing most people notice when entering Erebus is the complete lack of natural light. Without a flashlight or a flare, you will find yourself walking blind and just might end up lost forever in tunnels waist deep in vile, brackish sewer water... if you’re lucky. There are things swimming in the water. Things that have been living just fine without strange foreigners clumsily stomping through the water and waving around harsh, blinding light sources. Without being cautious, most newcomers will be pulled under the water by unspeakable horrors, never to be heard from again.
Erebus Traits:
Objective Directional Gravity: The strength of gravity is the same as on the Material Plane. But gravity is oriented toward wherever your feet are pointing. Thus, there is no normal concept of floor, wall or ceiling. Any surface can be a floor if you treat it like a floor.
Normal Time.
Infinite Size: While there are some closed off tunnels, the pipes of Erebus stretch off into the darkness with no apparent source or destination.
Alterable Morphic: For some strange, unexplained reason, this outer plane cannot be shaped by divine will. Naturally, this makes it very unpopular as a home for deities. Not that all but the most unhygienic gods would even want to call this place home anyway.
No Elemental or Energy Traits.
Mildly Chaos-Aligned: Lawful characters on the plane of Erebus suffer a -2 penalty on all Charisma-based checks.
Normal Magic.
Erebus Links:
Permanent portals exist between various planes and Erebus. By far the easiest way to get to Erebus is to hop on a boat in the river Styx and just keep sailing downstream. You'll get there if you wait long enough. Oddly enough, anything flushed down a toilet has a 1% chance of ending up in the endless sewer, regardless of whether your indoor plumbing is connected to a public sewer or septic tank.
Erebus Inhabitants:
Despite the first impression that Erebus is a quiet plane full of still, smelly water, the place is actually teaming with life. The natives of the endless sewers mostly fall into two categories: the creatures that live in the water (which can included monsters like aboleths, chuul, krakens, tojanida, dire crocodiles, etc.) and the creatures that live their lives hanging, climbing and swinging from the endless rusty pipes (chokers, araneas, phase spiders, monstrous spiders, gricks, etc.). Few, if any, humanoids can be found in Erebus without some serious searching. They are there, though. Most of them tend to congregate in the pseudo-city known as The Sanitation Plant.
Erebus Petitioners:
Petitioners are a rare sight outside of the Sanitation Plant since most are quickly pulled under the vile water and eaten within moments of arriving on Erebus. The few that survive look much like they did in life, with one major difference. They lack eyes or any other visual organ. This doesn't seem to bother them at all. They can even discern colours and read. Petitioners, when found, are always carrying out some predestined task. It can be anything, but it usually involves replacing pipeline, treating sewage, operating the machinery in the Sanitation Plant or something else that is important in maintaining the continued operation of the Endless Sewers. Erebus petitioners have the following special traits:
Additional Immunities: Cold, Poison
Resistances: Acid 20, Electricity 20
Other Special Qualities: Darkvision 60 feet, blindsight 40 feet (as the grimlock ability).
Erebus Features:
When Erebus mysteriously took Pandemonium's place in the Great Wheel, it started out as a relatively small plane. It consisted of only one layer with wet, concrete tunnels underground and a sky full of old rusty pipes with varying sizes and shapes pumping Styx water to places unknown. However, over the past few centuries, the Endless Sewers became more ‘comfortable’ with its position in the outer planes and grew in size. As time went by, the underground tunnels and the pipeline sky grew farther and farther apart. Eventually, Erebus divided into two layers: the long and complex stone tunnels of Cesspool and the infinite space of old rusty pipes known as The Iron Jungle. Both layers have no natural light.
The Iron Jungle
There is no up. There is no down. In this layer of Erebus, direction has no meaning. All that's here is pipes. Copper pipes, iron pipes, aluminium pipes, steel pipes as far as the eye can see, each one stretching on forever into the darkness. No two pipes are the same size; they can range from a diameter of several miles to no thicker than a strand of hair. Primate-like fiends have been seen swinging from pipe to pipe not unlike a jungle creature would swing from branches and vines, hence the name for this layer.
Cesspool
It’s easy to see how Cesspool gets its name. This layer literally looks like a giant collection of sewer tunnels that never end. In this layer, pitch-black stone tunnels weave in and out of themselves. Merging or dividing. Widening or narrowing. If it wasn’t for the lack of deafening wind, one could almost mistake this layer for one of the wetter tunnels of Pandemonium. When entering this realm, you will always find yourself waist-deep in the vilest, stinking water that you have ever had the displeasure of contacting. One should also note that this is the most dangerous layer as well. Vast arrays of aquatic creatures call this stinking filth-hole home, many of which are carnivores that have developed a taste for exotic meats (read: YOU!).
The Sanitation Plant: This is the final destination of the river Styx. The Sanitation Plant is an enormous industrial complex the size of a large city. Millions of gallons of Styx water are pumped into the Plant everyday for some enigmatic process called ‘refinement’. The smell of smoke and the screaming of loud machinery are always present as the petitioner workers work themselves non-stop to make sure that the complex continues to run smoothly in its operation. They don’t eat. They don’t sleep. They just work. When asked why they do this, most petitioners answer with something along the lines of ‘I work because it my job. Now, go away! I’m behind schedule!’ On-job accidents are common as the workers are prone to falling off of catwalks or getting caught in the machinery and ground into a fine paste. Yet, work never ceases. If one worker is killed, another one will always take his place in 1d4 minutes and continue his predecessor’s job as if nothing had happened. If a worker is forcefully removed from his post, he will do everything in his power to return. If return is not possible, the petitioner becomes suicidal.
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Reminds me of the Hive Worlds in WH40K.
Good stuff Bob
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