Gehenna

Gehenna, also known as the Fiery Slopes of Gehenna, the Fourfold Foundries, the Fires of Perdition or the Bleak Eternity of Gehenna is a plane without charity, mercy or pity. This plane is located in the Outer Planes and exists between the Nine Hells of Baator and the Grey Wastes of Hades, this sets the alignment of the plane to Neutral / Lawful Evil. There are four layers to this plane, each of a volcano floating in a void of nothing with each volcano being different.
The four layers, Khalas, Chamada, Mungoth, and Krangath, are all incredibly dangerous to climb with no slopes being inclined less than 45 degrees. All those layers, except for Krangath, feature active volcanoes that are constantly spewing pyroclastic ejecta, magma, snow, and even more environment danger. Even the ground itself burns, causing many unprepared visitors to suddenly burst into flames upon arriving on Gehenna.

Ecosystem

An Outsider’s Perspective Most people who have visited have come back to tell others that visiting this plane just isn’t worth it unless you have something to prove. The lava flows, the burning ground, the ash, and even the snow do everything in their power to destroy anyone and anything that visits this plane. The ground itself is burning hot and will ignite anything flammable that touches it.
Most visitors to this plane are here for a very specific reason and then just as quickly leave this plane. While this plane may not be the most inhospitable plane, like the Positive or Negative Energy Planes, for many travelers this plane is just far too dangerous to visit. For those who are foolishly brave, or have reason to come here, find a plane that lacks compassion, charity or pity. Finding civilization sprinkled across the plane isn’t difficult, though the inhabitants are just as bad as the plane, demanding compensation before providing any help, even if its just directions to an inn.
A Native’s Perspective Planes of Conflict, 1995 TSR Inc. Planes of Conflict, 1995 TSR Inc.
Whereas most would see this plane as chaotic and horrifying, for those who reside on this plane there is a law to this plane, which makes sense as it is so close to the Nine Hells on the planar charts. The law is hidden through deception and power, those who are powerful enforce their laws and others are expected to follow it or be killed, either by the plane or by the one who claims to be in charge. Every petitioner is seeking to increase their power and many travel across this plane across the multiple layers to do just that.
Every creature here fends for themselves, and they are all looking to put in place schemes to destroy their rivals or visitors to this plane. Some creatures even claim that the plane is infectious in that manner because the plane lacks any mercy or charity, so those who spend any amount of time here act as such. Compensation must always be demanded before any kindness is shown, and even then kindness is only shown as far as the compensation goes.
The main inhabitants of this plane are the yugoloths who had a mass exodus several millennia ago from the Gray Wastes of Hades, though no one is quite sure why that is. After the yugoloths are the petitioners, the souls of those who have died and for their final rest are brought to this plane. These souls are called the refuse of the planes, the ones who were greedy and always grasping for more. Everyone on this plane is suspicious of each other, for everyone is trying to grow their power and are quick to betray anyone for any reason.
Atmosphere The spewing magma and lava of this plane light up each layer, casting shadows up into the air. A black, unending void wraps around each layer of this plane, with many claiming that if you go into the void you’ll never return. While each layer offers its own dangers, most agree that the first layer, Khalas, is the most hospitable out of all of them.
On Khalas, the River Styx and many other rivers flow across its surface, there are no lakes instead the water will splash over a waterfall and evaporate in the air as the heat from this plane immediately dissipates it. While many who travel across this plane might see the rivers to be an ideal way of staying cool on this plane, the rivers on Khalas have been poisoned by the heavy metals from the lava, any who drink from it suffers horribly as their skin begins rotting and sloughing off of them.
The other three layers are just as dangerous, though in their separate ways. The second layer, Chamada, features lava flows that are hundreds of miles wide, the third layer, Mungoth is so cold and hot that its snow and ash mixture burns skin on contact. The final layer, Krangath, is completely black and silent, this layer is of a dead volcano, and where as the others are horrifying hot, this layer is so cold that it freezes unprepared creatures where they stand.
Light The light of Gehenna is put out by the volcanoes on each layer, and days are marked by how brightly the lava emits light. As fresh lava pours forth, the brighter it gets and as it cools and hardens the light gets dimmer and weaker. This is a constant process of lava cooling, though most inhabitants agree that any single area sees about 2 hours of bright light and 22 hours of dim light every day as fresh lava pours around it and then begins to harden and cool.

Tourism

Travel to the Plane Traveling to this plane can be accomplished by the usual methods of finding a portal in Sigil, finding the corresponding color pool in the Astral Sea or by finding a portal on the neighboring planes of the Nine Hells and Hades. Everyone who arrives here through a portal arrives in the deepest tunnels and caverns in this plane, for only here are the pitch-black portals that lead in and out to this plane. Because every portal to leave Gehenna, and to travel from layer to layer, looks the same, that of a pitch-black void, most are marked by the yugoloths and the petitioners who live here. Though some of them are marked wrongly or they aren’t actually portals and what you are seeing is just the void far below the layer, it all looks the same. Many of the inhabitants make cruel entertainment out of tricking people into jumping into the void through these ‘portals’.
The other way of arriving on to this plane is to follow the River Styx and several ferrymen are more than willing to drive you down the river for the right price, though there are just as many that will leave you for dead and take all your coin. As soon as the River Styx arrives in Gehenna, it begins speeding up quite quickly, cutting channels across the top layer, Khalas, and there is a real danger of being dashed against rocks or tumbling over a waterfall. The most skilled ferrymen know the waters well, though there is always the danger you might fall into or just touch the River Styx and lose all your memories.
Traversing the Plane Traveling across this plane is surprisingly easy to prepare for unlike many of the other planes. Information is readily available for what dangers you might face and how best to protect yourself, of course, all the planning in the world won’t save you if you trip and begin falling down the massive slopes of the volcanoes. At that point, you have to hope you crash into a ledge or able to grab a sturdy enough outcropping before you fall off the layer.
While Gehenna is infinitely large like most other planes, the physical area that you can travel can be measured and each volcano is only a few hundred thousand miles wide. Most inhabitants do what they can to avoid being on the outside of the volcanoes, especially on the second layer Chamada where lava flows can be as wide as several hundred miles, wiping out anything in their path. Most travelers stick to the inside of the volcanoes, following old lava tubes, tunnels, and other passages though even that has its hazards. Tunnels rarely last very long as the magma from the volcanoes melts the rock and lava spills into the tunnels, or if you find an old tunnel, you might stumble across the inhabitants of this plane who will often figure out a way to trick or scheme you out of your valuables and even your life.
Gravity and Slopes Every surface on this plane is a slope except for what has been artificially created by its inhabitants. Every slope is at least at a 45-degree incline, with many being steeper or a sheer cliff. Falling is a constant hazard and is how many die on this plane if they can survive the intense heat and cold. Once a creature starts falling, they only stop if they hit a ledge hundreds of feet below them, though most creatures just keep crashing into the ground and tumbling down until they hit the base of the volcano and continue falling out into the void that surrounds every layer. No one is sure what is in the void, but those who fall in are never seen again.
The only places that aren’t sloped are temporary at best, carved out by creatures hoping for a restful night without the fear of tumbling down. Unfortunately for them, this plane will often destroy those ledges with avalanches, lava flows or an earthquake that will sheer it off the face of the volcano. Any creature unlucky enough to be on that ledge is buried by rock and lava, or fall off the volcano into the void. The only permanent artificial flat surfaces are protected by the yugoloths and their magics, these locations are fiercely defended by the residents against any who would try to take it from them.

Type

Plane of Existence

Location under

Lower Planes