Inn Between the Worlds

It may be an inn on a road in a Heroic Fantasy world, a Wild West saloon, a bar in a high-tech space station, or just a local pub -- or it could be all of these at the same time. The Inn Between the Worlds exists simultaneously in different worlds, universes and/or times, or perhaps just jumps around in the fashion of The Little Shop That Wasn't There Yesterday. Whether you can reliably return to where you came in varies.

Inns Between The Worlds, though they connect to some or all worlds, are not themselves part of any world. They are typically places of truce and/or sanctuary, and laws of physics and/or reality may be suspended as needed. (Quite a lot of them, for instance, are Bigger On the Inside.)

Sometimes Inns are used as a Framing Device for the patrons to tell strange and fantastic stories of their worlds. Sometimes it enables a Time Travel or Trapped in Another World plot, where the character leaves the inn through the wrong entrance (or the right entrance depending on your point of view). Perhaps it enables a Crossover for characters from different worlds or times to meet in a friendly environment. On rare occasions, if no one ever leaves, it may turn out to be a kind of afterlife.

Compare with:

 * The Little Shop That Wasn't There Yesterday: Also an island of the fantastic in the ordinary world, but Inns don't move around as much, are much more social than Little Shops (where your interactions are almost always limited to a single shopkeeper), and are less focused on the acquisition of magical items.
 * Bazaar of the Bizarre: More social than Little Shops but less than the Inn. The Inn is also not particularly focused on commerce (except food, drink, and sometimes rooms).
 * At the Crossroads: The Crossroads are where roads meet. The Inn is where universes meet.
 * Good Guy Bar

Contrast with:

 * Void Between the Worlds: When there's nothing outside reality.
 * Eldritch Location: A place outside reality that isn't hospitable.

Anime and Manga

 * The Nasuverse has the Cafe Ahnenerbe, a rustic little restaurant noted for its excellent curry, is noted as a "place of impossible meetings" since it connects to all dimensions of the Nasuverse. The end results of the meetings can be, well...eccentric. The one to blame is (as always when it comes to dimensional travel) probably Zelretch.
 * The Ahnenerbe is an accessible restaurant in Kara no Kyoukai, but in Episode 5 it gets used this way when say their farewells to each other at the end of the movie.

Comic Books

 * Book 8 of The Sandman (Worlds' End) is set in such an inn. Book 9 mentions that there are four.
 * The latest House of Mystery comic from Vertigo is set in one of these.
 * The second to last act of The Books of Magic takes place in there.
 * Warhammer has a comic series called Tales of the Ten-Tailed Cat set in a tavern like this.
 * The Oblivion Bar in Shadowpact, formerly a bookstore.
 * Munden's Bar in Grim Jack; in this case, it's a property of the city the bar is in, though Munden's itself gets more than its share of odd customers even by the standards of Cynosure.
 * The Transformers comics had Old Maccadam's Oil House, one of the best bars on Cybertron. It's run by the titular Maccadam, who is rumored to be one of the original thirteen Transformers (and thus a multiversal nexus in and of himself), and in one comic one of the backrooms served as a hangout for dead Optimuses from across the multiverse while they were waiting for resurrection. As soon as the Optimuses (Optimi?) got revived, a gaggle of dead Megatrons showed up. Notably, except for the dead Optimi and Megatrons, its patrons are unaware that they're dining in a cross-multiversal establishment.

Commercial

 * Sony made one that has various game characters hang out in a bar, who all end up cheering the player for being a great person who helped them in their time of need.

Fan Fiction

 * This Time Round, the Doctor Who pub outside continuity, a meeting place for everything in the Doctor Who Expanded Universe - and every canon they've crossed over with. Inspired by the Subreality Cafe, which is this for comics characters.
 * Arisugawa's Locket also exists simultaneously across many dimensions.

Literature

 * The Leaky Cauldron from Harry Potter qualifies. It's not in the Muggle world (Muggles can't see it) nor really in the wizarding world (it's in Muggle London), and leads to a portal between the two.
 * Callahans Crosstime Saloon and sequels are all about such a place. (Actually, Callahan's Bar is a perfectly normal location in spacetime, it's the patrons that come from everywhere and everywhen.)
 * Lady Callahan's is similar, but it is a brothel with a bar downstairs. Oddly, the innocent and regulated downstairs is so awesome some never take advantage of the other services available.
 * Ditto with Arthur C. Clarke's Tales from the White Hart, L Sprague De Camp's Tales from Gavagan's Bar, and Larry Niven's Tales from the Draco Tavern.
 * The Captain's Table Star Trek novels use it as a Framing Device. This particular version can only be reached by those who hold or have held the Captain rank (or its equivalent) which, coupled with the fact it touches all of time and space, means it sees all sorts of visitors -- like a Captain of a Roman Legion. About the only permanent occupant is a dazed man in a tattered uniform who sits in a dark corner staring into nothing and mumbling about icebergs... yes, that's right, it's the captain of the Titanic, who remains in the Captain's Table due to a mixture of having mentally broken and the fact that stepping out the door will place him back on the Titanic's deck as it finishes sinking into the ocean.
 * Oh, and Cap the bartender. Don't forget about him.
 * Milliways, the Restaurant at the End of the Universe from ~The Hitchhiker's Guide To The Galaxy~, after a fashion.
 * Also the Massive Multiplayer Crossover LiveJournal . RPG named for it, although whether they're actually meant to be the same bar is unclear.
 * And don't forget the Big Bang Burger Bar, at the other "end" of the universe...
 * Played with in Phyllis Ann Karr's A Night at Two Inns in the second of the Sword and Sorceress anthologies, where there are not one but two such inns opposite each other. Each claims to be Heaven, and denounces the other as Hell.
 * The 1988 Hugo-Winning short story Why I Left Harry's All-Night Hamburgers by Lawrence Watt-Evans features a hamburger joint that exists in the same spot in nearly all universes, making it a popular late-night hangout for inter-dimensional travelers.
 * Alfred Bester & Roger Zelazny's Psychoshop has a similar nature, but instead of a bar, it's a sort of pawnshop, "where you can dump any unwanted aspect of your spirit as long as you exchange it for something else".
 * The Old Phoenix Tavern in several works by Poul Anderson, most famously A Midsummer Tempest -- where it introduces a character from his Operation Chaos and another from Three Hearts and Three Lions. (This enables Anderson to tell curious readers what happened to the hero of the latter, without writing a full-scale sequel).
 * The short story The Inn at Mount Either takes place at an inn located on an inter dimensional mountain and is connected to alternated versions of itself. The story deals with the protagonist searching for his wife after she gets lost among the infinite worlds. It is implied that the wife he found wasn't "exactly" who he was looking for, and he may have not returned to the right Earth.
 * The Draco Tavern in several Larry Niven short stories is a pub in Earth's main spaceport, equipped for a very diverse range of customers.
 * Cowboy Feng's Space Bar And Grille, from the Stephen Brust novel of the same name, jumps from world to world (and time to time) whenever an atomic bomb goes off nearby. And that's been happening a lot lately...
 * The House of Red Fireflies is a brothel between the worlds, currently there are three short stories set there.
 * Honest John's in The Riftwar Cycle. It's reached from the Hall of Worlds, by stepping off the path between certain doorways. You have to know the right spots... or else.
 * Any of the several right spots. Or else what is never really elaborated upon, but nobody ever comes back from it. Nobody ever says how, exactly, it was found, or for that matter how it exists.
 * This isn't exactly the case of Hotel Babylon in Deep Secret, but it does bend the laws of physics (like you could make seven right hand turns and still not end up where you came from) since enchanters keep using magic and opening portals to other worlds from there.
 * A. Bertram Chandler once had Space Navy officer John Grimes inadvertently cross universes to a club for fictional naval personnel -- though the original rules were bent a bit to allow non-naval ship captains such as Ahab to hang out there (it's hinted that Commander Bond had to strong-arm Captain Queeg somewhat to make him stop objecting to Ahab's inclusion). Jeeves is the chief servant at the club, is fully aware of the fictional nature of all involved, and asks Grimes (approximate quote): "The question is, sir, are you an enduring creation?"

Live Action TV

 * The Void from Doctor Who which is stated by the Doctor as sometimes being referred to as Hell.
 * And in the episode "The Doctor's Wife", they visit the bubble universe which the Doctor describes as a "sinkhole in reality". He strongly tries to emphasize that it is not a universe per se, but just outside the universe.
 * The "Astral Diner" of the Stargate: SG-1 episode "Threads".
 * This is an example of A Form You Are Comfortable With.
 * Arguably, Al's diner/bar in Mirror Image, the last episode of Quantum Leap.
 * The titular diner of Nightmare Cafe starring Robert Englund was an example of a sentient Inn Between The Worlds.
 * Hikari Studio in Kamen Rider Decade, which serves as Tsukasa's method of travelling between the parallel worlds.
 * The pub in Life On Mars, as revealed in Ashes to Ashes, is actually
 * On Fringe,.

Tabletop RP Gs

 * Sigil from the Planescape D&D setting is the city equivalent of this trope -- located on the inside of a torus on top of an infinitely tall spire located in the exact center of the planes (who are infinite in size -- no, don't think too hard about that one), it is simultaneously connected to almost everywhere in D&D cosmology through its virtually infinite amounts of portals, all of whom differ in size, place they lead to and what opens them. Because of this, Sigil is a place where one can expect to find almost anything. It's still a somewhat normal town with everyday life and time that flows normally, however. Well, as much "normal" as can be a city built on the inside of a torus so that you can see it curving above you, where belief can shape reality, visited every day by strange creatures from all over the multiverse, ruled by an enigmatic being who kills those who worship her by pulling her sharp shadow over them...
 * The World Serpent Inn mentioned in several Forgotten Realms sourcebooks was built in its own demiplane by an archmage from Toril, Arcane and Illithid as a neutral ground when Sigil turned out to be too violent and inconvenient for quiet business and rest. Not only is it connected to many worlds, but (unlike Sigil) is accessible to powers, and some gods visit it to relax and chat with creatures they deem interesting. It's a form of Good Guy Bar, since no one wants to annoy peacefully grazing deities, and some clients in a common room can turn out to be gods on a tea-break. And even if there aren't any, The Bartender is an avatar himself--if some god just likes to meet new people and thinks it's funny, why not?
 * The Dungeons and Dragons Mystara campaign world has two: the Comealong Inn and The Inn Between the Worlds. (Originally just one, they were split thanks to a Retcon.) Other campaign settings have the World Serpent Inn, which is actually theorized to be a sentient demi-plane.
 * Among the many, many items in the 2nd Edition Encyclopedia Magica is the "Awl, Inn", a cobbler's tool that could be used to open a portal to such an Inn.
 * Terra City, from Chaos, is more of a Multiverse-sized ecumenopolis-city between the worlds. Warriors, wanderers, travelers, traders, troubadours, and every other sort of strange folk come and go here every day from the most distant multiverses. It's probably not hard to guess that Terra City has hundreds of septillions (at a low estimate) of bars, inns, pubs, watering holes, and other, much stranger types of establishments, different ones of which are popular with beings from different parts of the omniverse.
 * Several roleplaying forums have an Inn Between the Worlds or similar subforum for players to meet up and chat in character despite playing in different campaign worlds.
 * There is a GURPS worldbook where every adventure starts in a bar where going to the bathroom can land you literally anywhere in the multiverse.
 * GURPS also has a semi-sentient Victorian Era-esque Gentleman's Club which has hundreds of doors which all lead to various alternate universes, listed in the original Time Travel supplement.
 * And the newer Infinite Worlds books gives a brief mention of the Infinity Patrol bars. The patrons might all be from the same world, but they've been just about everywhen.
 * The eponymous Floating Vagabond from the RPG Tales From The Floating Vagabond is a variation of this--it only exists in one place and time, but has a device that will randomly cause people who enter other bars in any time, reality, or location in the universe to end up there... and once it's happened once, they can intentionally cause it to happen whenever they enter another bar from then on.
 * "Chez Régis" in In Nomine Satanis/Magna Veritas, where angels and demons can drink without fighting each other.
 * Though not precisely between worlds, the Hollows that characters in Changeling: The Lost can build do share characteristics with this trope: Built in a parallel dimension called the Hedge, a Hollow can, and usually will, open into both worlds, and its doors can be separated by vast distances in Earth-side terms (a Hollow could have entrances in Boston, London, Tokyo, and Moscow fairly easily).

Video Games

 * The Quester's Rest in Dragon Quest IX. It is visited by several Cameo characters from previous Dragon Quest games; and you can meet with and travel with Alternate Universe versions of yourself. (IE, other players who have the game.)
 * "Pocket D" is a nightclub in a small Pocket Dimension, in the MMORPGs City of Heroes and City of Villains (and City of Heroes Going Rogue). It's accessible from multiple points in either games, and allows characters from all three to interact in a neutral environment (Co H and Co V have multiple PvP zones otherwise).
 * It's also the designated location for special events, including the Winter and Spring Events.
 * Does this really count though? Both the rogue isles and Paragon city, last I checked were in the same universe.'
 * Pocket D is called "Pocket D" as an abbreviation for "Pocket Dimension." It's not anywhere on Earth, or even the same plane of existence as Paragon City and the Rogue Isles.
 * In the earlier part of Chrono Trigger but (suspiciously) right after the number of characters playable at once exceeds three, time travel happens through portals at the "End of Time", which is a claustrophobic collection of several connecting rooms. It's not nice enough to be an Inn, but it is an important juncture point between the eras of time.
 * There is some kind of explanation given about why you end up there to justify why it happened only as you got four characters in your team.
 * The fact that it's the juncture point between points of time is hilarious when you remember that it's the end of time. In other words, the fastest way between two points of time is to go to the end and back.
 * This isn't as surprising when you take into account the fact that the "End" of Time is really just a convenient moniker for a place that simply exists outside of time. It's easy to travel between points in time when you simply exit the continuum and re-enter it at a point of your choosing.
 * Nor is it meant to be the fastest way. It's little more than a temporal divide-by-zero error. (Remember how in Wild Arms, you would get to the Abyss by beating the crap out of the teleporter?)
 * The aptly-named Tavern of Time, located in the Caverns of Time in World of Warcraft. It's simply a little house with a bartender NPC in it. The "between the worlds" part comes from the fact that the Caverns of Time are the home and workplace of the guardians of time and nearby NPCs are Unstuck in Time.
 * The mage's tower in Stormwind contains a portal leading to large room with tall Cathedral ceilings, where the mage trainers do their studies. If you listen to some of the mages' conversations around the district, they talk about stabilizing portals and creating small universes.
 * Traverse Town, in Kingdom Hearts, serves as a refuge for survivors from all the different worlds that've been destroyed by The Heartless, and a launching point into the game's multiverse. The "corridors of darkness" that are ripped open during a world's destruction tend to take people to Traverse Town by default, which is how the hero first arrived after escaping his Doomed Hometown.
 * The Shin Megami Tensei Persona series has the "Velvet Room," a sort of cabaret lounge located "between consciousness and subconsciousness". It can only be entered by those who possess a connection to the spirit world.
 * In the Golden Sun series, there is an arena that you are able to go to anywhere from the main menu. The characters inside seem to acknowledge its existence, yet it is never visited in the main game of either of the games.
 * The Cafe of Broken Dreams in Fallout 2 is the fourth-wall breaking version of this. It's a random encounter, but if you get it, you meet up with the NPCs of the first game, engage in jokes about character models, and get Dogmeat back.
 * Super Paper Mario has the towns of Flipside and Flopside, which are said to exist between dimensions.
 * Final Fantasy V has a stranger than usual example in a town that disappeared out of existence for centuries,

Web Comics

 * The Cross Time Cafe webcomic exists to let webcomic characters meet up outside their own continuity.
 * The Pub Stub from Goats.
 * In Achewood, travelling between Earth and Hell is done through the restrooms in Friendly's.
 * The Adventures of Dr. McNinja shows Purgatory as being a Restaurant Between the Worlds, in which one eats one's venial sins to purge them from the soul. However, since the restaurant is infinite and there's only one waiter, the process can take millennia.

Web Original

 * The Sands of Time in Star Harbor Nights is an extradimensional tavern. Its existence has been used to justify at least one "incredibly pointless cameo" from a minor Tales of MU character.
 * Ouroboros a.k.a. The Pub in the Hub of the Multiverse, from AH Dot Com the Series.
 * Game FAQs has an invite only board called "Restaurant at the End of the Universe"
 * "The Inn Between Realms" was a thread in the now defunct Amazon.com Science Fiction & Fantasy discussion board and its user-created continuation at Delphi that grew spontaneously from casual chatting through roleplaying to collaborative storytelling. It was mostly set in the titular Inn which, of course, was an example of this trope. How exactly it existed "between realms" wasn't entirely clear, but one explanation was that it carried with it a small area of geography whose edges linked to random places on various worlds at different times, without visible transition lines. In any case, everyone bringing in their various original characters reflected the world-connecting nature of the location. The story remained mostly an insider thing, but as a handful of the collaborators are published authors (no big names... yet) and many others are prospective, the setting may crop up somewhere yet.
 * This is the general idea behind "dressing room" RPGs on Livejournal - the only difference being that your stay there is usually a lot longer than in other examples of this trope. The benefit of this setting is that players can come and go as they please; when a player wants to stop playing, they can simply stop posting and other characters will simply treat the disappearance as the dressing room sending your character home.
 * Stan's Place in I'm a Marvel And Im ADC is this between the Marvel Comics and DC Comics universes.
 * As well as the real world, indie comic distributers like Dark Horse Comics (where Hellboy hails from), and probably many more.