Castiel: [This strip club] is a den of iniquity. I should not be here.
Dean: Dude, you full-on rebelled against Heaven. Iniquity is one of the perks!
Also known as a "house of ill repute", a Den of Iniquity is typically a room, auditorium, or stadium in the Evil Overlord's Evil Tower of Ominousness or Island Base where all sorts of sin and wrongdoing takes place. Although towers are in short supply nowadays, if the Big Bad happens to make and/or enforce the laws they might have one in their mansion (but explaining them to less debauched guests might be tricky).
The level of debauchery will vary according to the setting in question; family-friendly stories might make it a lounge for the Mooks to gamble, get drunk, and brawl (not necessarily in that order), while Darker and Edgier works might go for rape, torture, and blood sports.
The Den of Iniquity is often a hangout for the Mooks or Faceless Goons who need something to keep them entertained when they're off-duty. On the other hand, whether the Big Bad or The Dragon indulges in the debauchery depends on where they stand on the Sliding Scale of Antagonist Vileness.
Often populated with the Paid Harem and Bodyguard Babes. The Den Of Iniquity isn't restricted to "evil" characters (as Miss Kitty can usually attest), but most heroes will simply find it beneath them.
- Babel Tower from the beginning of the second season of Code Geass. Gambling, blood-sports, waitresses in bunny-girl outfit... and particularly rich and influential guests could indulge in 'rabbit-hunts'. It's never specified exactly what that means for the caught 'bunnies', but one can make reasonable guesses. Unfortunately for one mafia-boss, however, he happened to catch a Killer Rabbit...
- The Amazon Trio of Sailor Moon Super S has a more subdued example in the form of a bar with a lone saxophone playing to lounge in-between missions.
- The late chapters of Genocyber feature the political elite hanging out in a secret, luxurious and decadent bar with drugs, prostitutes, gambling and torture shows. It serves to drive home the stark Orwellian dystopia the world has turned into, with the powerful people carrying on lives of luxury and excesses while the proletariat is constantly watched, exploited, killed and made miserable.
- Hellblazer: In "Mortification of the Flesh", we learn that the Vatican has one, specifically, a room enchanted to be hidden from the eyes of God so that whatever is done in there isn't a sin. Built by Pope Alexander VI, who you may know better as Rodrigo Borgia. And the room certainly lives up to its reputation, having seen theft, fornication, murder, demon summoning... in that chapter alone.
- In L'épée de cistal, there is one that is also a "stock exchange of sins": the minions shout the name of one of the Seven Deadly Sins, and by that means influence people all around the would to commit those sins.
- Old Town in Sin City is an entire city district of iniquity, what a Red Light District would be if it was openly owned by the ones providing the "entertainment".
- A very family-friendly version of this appears in The Smurfs comic book story "The Gambler Smurfs", as Papa Smurf discovers that the Smurfs have set up a private gambling room in the village.
- In the Empath: The Luckiest Smurf story "Smurfed Behind: The Other Side Of The Mirror", Tapper's Tavern in the Mirror Universe version of the Smurf Village is pretty much this, with gambling, smoking, fighting, lots of obscene language, and immoral affections going on between the Smurfs. Not that the village itself is any better by comparison.
- The opening song in Aladdin (yes, the Disney version) has the protagonist in a place with some scantily clad harem girls, who clearly know who he is. (Far from the only example of Getting Crap Past the Radar here.)
- In Toy Story 3, there is a humorous example of a bunch of 'bad' toys hanging around in a vending machine, betting with Monopoly money and triple A batteries. They use a "Speak-And-Say" toy instead of a roulette table.
- Xerxes' royal pavilion in 300, filled with drugged courtiers and all forms of sex. And pot-smoking goat-headed servants.
- Tiberius's mansion in Caligula takes this Up to Eleven.
- Thulsa Doom's orgy chamber in Conan the Barbarian (1982). Goes from creepy to horrifying when you notice exactly what's on the menu in there.
Subotai: So this is paradise.
- Tony Stark's jet is a PG-rated version in Iron Man, complete with drinks, stripper pole and lascivious dancers.
- Return of the Jedi has the audience chamber in Jabba's Palace, with musicians, live dancers, chained slave girls, and a rancor pit where unsuspecting victims were thrown in for the audience's amusement.
- The hideout of the Foot Clan in Teenage Mutant Ninja Turtles (1990) contains a room where underage teens smoke and gamble.
- Herod's throne room in The Young Messiah is filled with dancing girls, witches, and lizard eaters.
- Ctuchik's tower in The Belgariad is described as having several levels, one for each of his "exotic perversions". They include torture, wealth and one which the hero isn't allowed to enter
- In The Dresden Files, the psychic 'vampires' of the White Court maintain Club Zero, a 'club' where pretty much anything goes: sadomasochism, drug use, every alignment of sexual activity, gluttony, booze of any sort, anything you want is available, and doesn't even cost that much in terms of money or the like. As Harry recognizes, you can find anything you want in Club Zero...except fulfillment or meaning or love.
- Anne Bishop's Ephemera novels have a Landscape called the Den of Iniquity. Described as a "carnal carnival" it's actually not a bad place, and the villains aren't welcome there.
- In Caliphate, Castle Noisvastei is a bordello operating under a fundamentalist Islamist state. Even though prostitution is punishable by death in states like Taliban, it's tolerated under Islamist-controlled Germany where female Christians are kept as sex slaves, but Muslims can also be sent there if their husbands divorce them. It gets much worse when there are also women brainwashed with mind-control devices to be used as cheap pleasure for the customers.
- Appears in The Eye of Argon as part of its massive collection of stock fantasy cliches.
- The Handmaid's Tale has Jezebel's, one of the few establishments left in Gilead where prostitution is permitted, but only to entertain the men. It passes itself off as a Smoky Gentlemen's Club to make it seem respectable in the face of the country's own moral hypocrisy as a supposedly "God-fearing" theocratic state.
- In Kim Newman's The Hound Of The Durbervilles, Professor Moriarty has his apartment and criminal base in a building which has as its first floor a brothel, and his number two, Colonel Moran, often indulges himself with the "other employees." Moriarty himself seems to have no sex drive.
- The term "Den Of Iniquity" first appears in Robert E. Howard's story "Texas John Alden".
- In Being a Green Mother, we find that Satan runs Mock Hell, where all types of sin can be indulged in, for "merely" a percentage of evil on your soul. Of course, when you get over 50%, you go to Hell for real. And it's no picnic. Of course, Satan being Satan, the pleasures aren't real, but the evil on the soul is.
- In The Letters From Nicodemus Herod is throwing a birthday party. Yes, that Herod. Booze pours like rain and shameless women dance all night long in the Den of Iniquity Herod's palace becomes.
- In Please Don't Tell My Parents I'm a Supervillain, Chinatown is a popular hangout for villains. Heroes stay away by truce.
- In the Star Trek: A Time to...... series, The pirates at Rashanar have one inside a derelict spaceship.
- Qibbu's Hut from the Republic Commando Series of books.
- In the book Third And Indiana, several of Diablo's hideouts are dens of iniquity.
- In Eagleheart, a bizarre bylaw makes it legal to do anything in the sky. Everything goes, up to and including murder. Naturally, a crime baron sets up a blimp as his base of operations where every type of crime is indulged and encouraged (except smoking, because of the hydrogen)
Chris Monsanto: So what you're saying is that everything is legal in the sky, and there's a huge crime blimp floating around? I wonder how I missed that.
- Tiberius' mansion in I, Claudius has one of these. The historical Tiberius, on the other hand, did not want and did not need one of these: an antisocial prick but able administrator, he preferred to spend his time mostly alone in his pleasure palace on the island of Capri, and according to Roman historian Suetonius, "indulging his pedophilic predilections" in private. Although later research showed that Tiberius went to Capri mostly because he wanted to hide from assassins and read in peace.
- The Knick features an opium den and a brothel, each of which ensnares various characters to greater or lesser degrees.
- Captain Pike's fantasy-planet in the original Star Trek's "The Cage."
- Supernatural sees Dean haul the angel Castiel to a brothel the night before said angel expects to perish in a confrontation with the archangel Raphael. The incredibly strait-laced Castiel reacts predictably.
Castiel: This is a den of iniquity. I should not be here.
Dean: Dude, you full-on rebelled against Heaven. Iniquity is one of the perks.
- It takes a hilarious turn when Castiel gets invited into a backroom with one of the girls. Moments later she runs out of the room shouting obscenities at him. Cas apparently read her mind, and casually told her it wasn't her fault her dad left her family when she was little. Dean and Cas are forced to leave post-haste when the bouncers show up.
- In the Book of Jeremiah (of The Bible), God condemns the Jews for treating His Temple like "a den of robbers" by breaking all the commandments except for "keeping the Sabbath holy" (by implication), declaring that "we are delivered" so that they can continue doing their abominations. (The same description is used by Jesus in the Gospels when He goes into the Temple to clean it out of the marketers and money-changers violating her sanctity — an image made much more vivid in the theatrical and stage productions of Jesus Christ Superstar.) In the apocryphal book of 2nd Maccabees, the Temple is actually reduced to this with the introduction of pagan revelry by Antiochus Epiphanes, including sex workers and roasting abominable meats.
- Dungeons & Dragons:
- Compared to the other layers of the Abyss, Shendilavri seems like a paradise, a picturesque land of gardens and marble cities beneath an eternal sunset, where the locals welcome visitors into a life of luxury, passion and indulgence. Unfortunately it's also the capital of Malcanthet, Queen of the Succubi, so its demonic citizens tempt mortals into increasing depravity until their souls are utterly corrupted, and beneath the beautiful facade are hidden dungeons and torture rooms.
- The Nine Hells of Baator are for the most part grimly dedicated to the business of combating the demonic hordes and processing damned souls, but on the layer of Maladomini is a place where devils can unwind. Baatezu can exchange harvested souls for a stay in the Carnival Eternal, where they can enjoy a reprieve from their usual duties ranging from one day for 9 souls to two millennia for 999 souls. "The tortures and debauchery engaged by vacationing devils are best described in vague terms to players."
- The Bad Taste Bears figures feature one of these◊.
- Dishonored has the Golden Cat, a pleasure establishment incorporating a brothel, bathhouse, and burlesque parlor, which is regularly visited by the aristocrats of Dunwall.
- Fallout 2 has the Den.
- Fallout 3 has Dukov's Place, a luxury building in the middle of post-apocalyptic Washington DC where its owner spends his days "eating, drinking, farting and screwing!"
- Fallout: New Vegas has Gomorrah, the brothel and casino run by The Omerta. It also serves as a Minigame Zone.
- Perfect Dark Zero's first mission is set at a Triad nightclub.
- In Splinter Cell: Conviction's co-op campaign, The Mafiya operate a strip club/brothel in a wine cellar beneath the St. Petersburg bathhouse.
- The Temple of Depraved in Warriors of Might and Magic. They're mainly demons worshippers and, for some reason, Gnolls and Ogres.
- World of Warcraft:
- The Den of Mortal Delights in the Black Temple raid instance in has parks, fluffy pillows, fountains, hookahs, silk curtains, nubile dancing blood elves, succubi and other female demons in stark contrast to the rest of the temple.
- Sunwell Plateau has a zone called the Den of Iniquity but it's empty and wrecked.
- In Talador, part of the city has Legion demons called "Concubines of Lust" and "Nefarious Madams", along with many mortal Legion members. It's pretty obvious what the purpose of the place is.
- Girl Genius: In a quick flashback Gil is shown someplace Tarvek seems to have considered to be Gil's Den of Iniquity in Paris, though it's implied to have been at some kind of bar, brothel or Opium Den so it wasn't in reality, surrounded by scantly clad women with something rather bong looking mostly cut off at the edge of the panel.
- Another low-key example: in one Kim Possible episode, Ron stumbles upon a room full of Drakken's henchmen sitting around taking a break.
- Looney Tunes: The Kit Kat Club in "Tin Pan Alley Cats" (1943) is deemed a den of iniquity by the pastor of Uncle Tomcat's mission. He pleads with the cartoon's protagonist not to go in "or you will be tempted by wine, women and song." The little guy's response: "What's de mattah wit' dat?!"
- The Venture Bros. showed a low-key example of this in the fourth season, a room inside the Monarch's cocoon where his minions would quietly gather for drinks on their downtime.