Carceri

The Tartarian Depths of Carceri or also known as Tartarus is an outer plane that is on the border of evil and Chaotic alignments.
Tartarus is a plane with a seemingly infinite number of planes across six layers. When entering Tartarus through a portal, one of its neighboring planes, or the ethereal plane, you will arrive on the top layer. Each layer has a string of worlds connected from one to the other. As you go down the layers, the worlds on each string get smaller and farther apart. In between worlds is an air-filled void making flying from one to another possible. Another option one has to reach the next world, on the top layer only, is the river Styx which travels mystically through the void. There is no sun, the planetoids do not rotate, but there is a faint and subtle red glow from the surface itself be it from sand or rock. Seasons and weather are wildly uncontrollable unless by a being of great power with one season that can last a year followed by the next only lasting an hour. On average, the terrain is not good for plant life to grow. However, plant life does grow rapidly, sprouting, spreading its seeds, and withers away, the entire process may be as quick as ten hours. To reach the lower layers, you have to travel to the deepest point of any given planet. There you will find some kind of portal which will take you to the surface of the subsequent planet one layer below you. Every layer of this plane has its fair share of demons, giants, and other monstrous beings but, the true rulers of this plane are the Demodands. These beings made of pure evil, and a force of primal destruction were banished to this plane by some unknown force. The Demodands were prisoners that became the wardens of their prison and will capture, kill, or enslave most beings that they come across on their orbs and layers.
Othrys
The first layer Othrys, is named after its series of mountain peaks. Each orb has a pair of mountains on opposite sides from each other. Each orb is about the size of the material plane and on average, 100 miles apart from each other. The two mountains on each side, both named Othrys, are about 50 miles high each and conjoin at the tip where there are physic defying citadels nesting at the points. The mountains were some of, if not the only pieces of solid land. The rest was covered in bog, marsh, or sand that was undisguisable from it sometimes highly expansive areas of quicksand. Most of the mountains have been claimed by high number of elementals and the bogs are home to seldom villages of people and monsters alike. Outside of that, the bogs and marshes are home to trolls, swarms of insects, and a toxic air that if breathed in for too long, two weeks, it will make you more intelligent but at the cost of making you more egotistical and a schemer. Othrys has a number of villages that are usually built on stilts above patches of swamp land. Raids and betrayals between villages were common and expected. If someone from the material plane were so inclined, they could make the travel to some of these villages where you can find any kind of forged document there is, attain plastic surgery for disguise purposes, and other services of deception.
Carcereri
The second layer of Carcereri is called Cathrys but known as the Scarlet Jungle. The worlds, or orbs, of this layer are smaller than that of Othrys and farther apart. Each semi planet is about 500 miles apart from each other. Unlike the dry rocks and warm sands of Othrys, Cathrys is covered in a lush and damp jungle with plant life that glows the same hue of subtle red like the orbs themselves. Despite the lushness of the jungle, it has the unpleasant scent of decay and rot. While exceedingly strong, the smell itself is ultimately harmless. The plants of the jungle however are not. Not only are most of the plant life carnivorous, but they also excrete or spit out an acid that is so strong that it can melt through metal in a minute, leather in minutes, and is deadly to most other organic life that has not adapted to it. The people who live on this layer consist of mostly nomadic tribe-like villages that will often raid one another for food . . . the food being the people from the other villages. Most of these villages exist in the plains or grasslands that are surrounded by razor like grass that could rip any unprotected being to shreds. The upkeep of roads are a vital essential for this layer.
Minethys
The third layer is called Minethys. The orbs of this layer appear orange. In truth, the orbs themselves still glow a deep red, but because of the yellow sands that float through the air, the orbs appear orange. Minethys is a cold and harsh desert with seldom life found. Harsh winds blow at a constant that in combination with the sand, is strong enough to slash the skin off of an unprotected being. Because of this, most beings either burrow underground or wear heavy clothing and armor to protect themselves. Coupled with this, the sand itself is also toxic, covering of one's face is also crucial for survival. Many tombs and signs of old cities lay buried in these sands that occasionally become temporarily unearthed. Occasionally, often once a week, a powerful sand tornado will form that is strong enough to send objects from one planet to the next which is about 5,000 miles away from each other.
Colothys
The fourth layer Colothys, is an almost entirely mountainous layer. Each orb was covered in mountain expanses and chasms that from bottom to top, stretch 100's of miles. Each orb is 500,000 miles away from each other, looking like dark red moons in the black void of the "sky". Climbing the outright sheer and often inverted slopes were almost impossible if not for the occasional natural plateaus, carved pathways between canyons that may be 1 foot across, or the old rope bridges that are often guarded or downright unsafe. Between the mostly demonic inhabitants of this layer there exists "cities" that have specific trade routes between each other. These routes are fiercely defended and fought for as they are the only thing that keeps them alive as none of them are self-sustaining. Also, near the deepest trenches is a prison run by the Demodands that can hold any prisoner.
Porphatys
Porphatys, the black snow, is the fifth layer. It is often referred to as the ocean layer. With each orb being the size of Exandria at this point and being millions of miles apart filled with black acidic clouds making navigation almost impossible. The orbs consist of a shallow ocean permeating throughout the surface with only small pockets of land being high as a sandbar and the occasional mountain peak. The sky is forever filled with black clouds that snow an acidic substance. The water itself is not deadly but unhealthy, an organic being could walk through the shallow ends but the metals and fabrics they carry would eventually melt away. The only sanctuary one could find from this black snow is the occasional cave that has been dug into the larger sandbars or mountain sides. The only inhabitants of this layer are those that would want to get out of it quickly.
Agathys
Agathys, the final layer, is unique from the rest. The orb is the smallest of any other, equivalent to the country of Whitestone. It is also believed to be the only orb of the layer simply because if there is another orb, it is so far away that it is impossible to find in the void. The surface of Agathys is frozen solid in several hundred miles of hard ice and therefore, does not dimly glow red like the other layers. Instead, the ice is black and occasionally, you may find a red streak through it. It is so called on this orb that breathing is difficult as breathing in too much can freeze your lungs. Staying in one place is also dangerous, if you were to bed down and try to sleep on this frozen sphere, your allies may find you frozen solid and completely encapsulated under the surface of ice. This layer does not have any inhabitants.