Hell, sometimes distinguished as "the Inferno" to differentiate it from other similar locations such as Hades, The Pit, and Naraka. Hell serves as home of Lucifer as well as his demons and fallen angels loyal to him. In this realm it's subdivided into nine layers, and each of these nine layers is governed by a "Great King" and each layer possessing their own politics and ranks which are eagerly filled by demons and fallen angels wishing to acquire more power and to gain the favor of Lucifer (or to one day usurp his throne).
Hell is set up as a cavernous descent, and the deeper one goes the colder it gets. Each layer of hell has its own unique features outside of the heat, and the lower layers end up housing the more powerful entities and also the more severely damned.
The ultimate goal as set up by Lucifer is to transform those in hell into demons under his control, and only through breaking them down and remolding them with the endless torment is this possible. As long as someone holds onto their humanity, they'll remain in hell to be tortured endlessly.
The land of those whose lives were not virtuous, and who must atone. Sinners who wander this land either repent, or are sent further into into a respective layer. Limbo is not a place for "evildoers" unlike the rest of hell, instead being a place where those who died committing sin have one last chance to repent in order to be saved. Only those who choose not to end up in hell forever.
As the most primal and animalistic of sins, Lust is the first layer of hell itself. It's separated into two regions within a single city. Within the majority of the city the lesser inhabitants live in a dysfunctional society of hedonism, those unable to defend themselves are often raped - both by the demons of Lust and by the other inhabitants capable of overpowering them. The innermost region of the city is only inhabited by demons of lust, and in the center is the 'Halls of Pleasure' which is a gigantic castle which is engaged in an endless orgy. This orgy is centered around Prince of Lust, Asmodeus, who rarely exits the Halls in favor of carnal delights.
Massive undulating walls of flesh and viscera create an organic cave-like network of passages and hallways, some leading into openings or clearings. Some regions have become infected and ooze pus while others are filled with blood like a cave may be filled with water. Deeper into the halls leads to a massive pit which drops for miles until finally ending at a deep ocean of stomach acid-like fluids where the screaming sinners are both burned and healed by the acid, and attempt to devour whatever may land into the acid. Above them are the demons of gluttony, partaking in a lavish banquet which Prince Beelzebub himself sits at the head of. Every so often the demons throw scraps down to the screaming sinners below to watch them quarrel and fight among themselves.
The opulent golden city of Greed is one which draws ire from those unable to make their ways to it...something which, many of the sinners in this region of hell face. They are stuck in the ghetto just outside the golden city, always desiring a way in. Each sinner partakes in lotteries and gambling, attempting to make their way to the top through the graces of 'lady luck'. These are all rigged to the point the numbers are so astronomically low for success, the demons rigging it occasionally force a winning outcome for some just to maintain the illusion of success being just out of reach. Mammon, Prince of Greed, sits in his lavish throne within his castle in the golden city, admiring his collection of gold and sending out demons to retrieve more.
An open colosseum stretches far with a full blown war on display for the spectators, all manner of violent and hateful acts done to one another in the name of one side or another. In the spectator stands, demons cheer on those fighting and may even join them for brief periods of time to make things more entertaining or to blow off some steam. In the viewing area with the best spot Prince Bæl sits, watching and hoping for an interesting fight though always let down as he watches with his hate growing day by day until a fight which finally can interest him shows up.
A region of hell not fully understood by many, the mausoleum of Heresy hosts many incredibly small tombs in which heretics are stuck inside through contortion and twisting them, putting them in a state which shifts between discomfort and numbness. This mausoleum is eerily quiet, watched over by Prince Mephistopheles who tasks his demons with ensuring that even if one of the contorted sinners were to escape their tomb, they'll only fall into a small manifested pit of hot tar before being stuffed back into their tomb, causing them to crave the numbness the suffocating tomb provides.
More devious and less invoked by passion like Anger, Violence is a massive ocean of boiling blood known as the Great Phlegethon with islands dotted in the surrounding area. Sinners are constantly trying to escape from the pain of being submerged in the boiling blood but are constantly pushed back in by demons flying over who use long pitchforks to jab at them. On the island exists the trees of suicide where those who have committed suicide out of a desire to obliterate their souls are transformed into frail old trees which bleed and cry out when broken. Frequently, demons will arrive to torment them as a reminder of the pain their death dealt. Prince Azazel presides over the realm and takes great pleasure in rending the helpless to ribbons.
A series of ditches expand over this vast landscape, the lands of fraud are one of the lowest and darkest of the layers. Sinners are buried accordingly depending on the severity of their fraud, those who sought to defraud others for personal gain have their arms and legs buried with their back and head visible above the dirt - upon which they are scourged by demons. Those in higher positions of power who used fraud and their position for higher aims are instead submerged in boiling tar and feces, their open wounds from scourging being regularly smeared with salt. Prince Malebolge presides over the fitting 'land of ditches'.
Last of the layers where the ruler of hell himself resides, only those who were willing to betray their fellow man, their country, or their faith end up within Treachery, a frozen and rocky wasteland where a pool of frozen water surrounds the ruler of hell - within this water is the submerged bodies of those daring enough to betray the trust bestowed upon them.