Den of Iniquity

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, but most heroes will simply find it beneath them.

Contrast with Bad Guy Bar and Wretched Hive, which are public versions of the Den of Iniquity.

Anime and Manga

 * 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.

Film
"Subotai: So this is paradise."
 * 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.
 * Thulsa Doom's orgy chamber in Conan the Barbarian. Goes from creepy to horrifying when you notice exactly what's on the menu in there.


 * Xerxes' royal pavilion in 300, filled with drugged courtiers and all forms of sex.
 * Tony Stark's jet is a PG-rated version in Iron Man, complete with drinks, stripper pole and lascivious dancers.
 * 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.

Literature

 * The term "Den Of Iniquity" first appears in Robert E Howard's story "Texas John Alden".
 * In the book Third And Indiana, several of Diablo's hideouts are dens of iniquity.
 * 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 Star Trek a Time To... series, The pirates at Rashanar have one inside a derelict spaceship.
 * The Star Trek Vanguard Expanded Universe series has one aboard the Omari-Ekon, the Orion ship under registry to Ganz.
 * Qibbu's Hut from the Star Wars Republic Commando Series of books.
 * 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, anthing 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 fulfilment 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.
 * Appears in The Eye of Argon as part of its massive collection of stock fantasy cliches.

Live-Action TV
"Castiel: This is a den of iniquity. I should not be here.
 * Captain Pike's fantasy-planet in the original Star Trek the Original Series's "The Cage."
 * Tiberius' mansion in I, Claudius has one of these.
 * Tiberius's manision in Caligula too, Up to Eleven.
 * 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 "indulging his pedophilic predilections" in private.
 * Supernatural:

Dean: Dude, you full-on rebelled against Heaven. Iniquity is one of the perks."

"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."
 * In Eagle Heart, 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)

MMORP Gs

 * The Den of Mortal Delights in the Black Temple raid instance in World of Warcraft 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 its empty and wrecked.

Music And Sound Effects

 * On each studio-album-proper, Joy Division had a song describing one: "Day of the Lords" on Unknown Pleasures, and "Atrocity Exhibition" on Closer (the latter's title is a Shout Out to J.G. Ballard).

Toys

 * The Bad Taste Bears figures feature.

Video Games

 * Fallout New Vegas has Gomorrah, run by The Omerta. It also serves as a Minigame Zone.
 * The Temple of Depraved in Warriors of Might and Magic. They're mainly demons worshippers and, for some reason, Gnolls and Ogres.

Western Animation

 * The Venture Brothers 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.
 * Another low-key example: in one Kim Possible episode, Ron stumbles upon a room full of Drakken's henchmen sitting around taking a break.