Vanishing Village

A plot that features a location that only appears or is accessible for certain periods of time. Frequently the home to a Lost World or civilization, it is usually found accidentally by "outsider" characters. Common features of the subsequent plot include one of the outsiders falling in love with a native, and/or the outsiders being required to leave within a certain period of time, or be trapped there.

Many examples are in reference to the 1947 musical Brigadoon, about two American tourists who stumble upon the mysterious town of the same name.

Compare The Little Shop That Wasn't There Yesterday.

Anime & Manga

 * The anime series Brigadoon Marin and Melan has the same name as the play in the title and a world sort of similar to it. It also has robot gunsword-slingers from another dimension.
 * The second Read or Die manga (Read or Dream) featured a ghost library that appeared to the living once every ten years. Of course, you could visit it all you liked after you were dead, as long as you brought your books back on time.

Comic Books

 * One issue of DC's post-Zero Hour Legion of Super-Heroes features the planet Steeple, which is somehow only accessible for a limited period of time every ten years due to a black hole. Legionnaire Karate Kid ends up missing the window out of reluctance to leave an injured teammate, although they both ended up getting rescued anyhow.
 * Tyroc in the 1970's came from the island of Marzal, which had a similar problem, the name Brigadoon even being referenced in the story's title.
 * Pre-Crisis Planet Rokyn had just such a relationship with the universe.
 * Captain Marvel Jr. visited the "City in the Mirage," which appeared once every thousand years, in a 1975 Shazam comic that also saw his older counterpart visiting a future where giant rats have taken over the world.
 * Done in Sonic CD and later the Sonic the Comic series about the mysterious planet that appears during a yearly eclipse and disappears when it ends, with the majority of the plots being focused on escaping the planet before it fades back into whatever dimension it came from.
 * Averted by Robotnik in Sonic CD, who chains Little Planet to Earth.
 * The Usborne Puzzle Adventure book The Vanishing Village has the protagonist searching for a village of this sort (as the title may suggest).
 * One of these makes an appearance in Black Moon Chronicles. Demons use the protagonists' unwitting stay there to stuff main character Wismerhill's first girlfriend into the fridge.

Film -- Live Action

 * Pleasant Valley, in Herschell Gordon Lewis' "B" horror film Two Thousand Maniacs!

Folklore and Legend

 * Common in folk stories about The Fair Folk, regarding the way into Fairyland.

Literature

 * While it's never been relevent to the stories, The Discworld Companion claims the country of Chimeria (which gets referenced briefly in The Colour of Magic, and never gets mentioned again) is a brigadoon, as is the Lost City of Ee (which is why so many adventurers have discovered it, only to lose it again almost immediately).
 * Forever After, an anthology with Roger Zelazny's name on front, features an assassin on a quest to  This city comes and goes, and no one is sure if he'll make it out.
 * In the Secrets of Droon book City In The Clouds, the floating city of Ro only appears once in hundreds of years, and the heroes (and the villains) are in serious danger of getting stranded there.
 * In the Deverry series by Kathrine Kerr, the dwarven island of Haen Marn teleports away when its inhabitants are threatened, disappearing for years at a time until ithe island deems it safe to return
 * The Humanx Commonwealth novels apply this trope to an entire planet, Quofum.
 * The Humanx Commonwealth novels apply this trope to an entire planet, Quofum.

Live Action Television

 * Deep Space Nine: The planet Meridian appears only once every 60 years.
 * Farscape has an episode with a group of planets at the centre of a time anomaly where time passes much faster than in the wider universe and which only become accessible for an hour or so every fifty-five years. It is suggested that since the spaceship Moya is part-way into the anomaly, it may be experiencing a milder but still serious level of time displacement.
 * Played mostly straight (as straight as the series could muster, anyhow) in the second season episode "Brigadoom" of Lexx, which was also a Musical Episode.
 * The characters in Sliders are driven from one dimension to the next by the fact that each world is essentially one of these.
 * Though this is only because of a malfunction with the device they use to go from world to world. If it worked right, they'd be able to come and go as they please.

Tabletop RPG

 * Exalted has a spell specifically to produce the Brigadoon effect.
 * In the GURPS Infinite Worlds sourcebook, places like Brigadoon are referred to as 'shiftrealms', and range from the archetypal 'town from the mists' to a subway car that always knows where its passengers need to go.

Video Games

 * In the Castlevania games, Dracula's castle (and the man himself) return every 100 years... in theory. In practice, various cults are always resurrecting them sooner.
 * The city of Dawn in Ultima III. "Dawn lasts for but a brief moment."
 * Minus the "must escape or be trapped" part... the city's got a really favorable timeflow differential.

Western Animation

 * Spoofed in an episode of the Animated Adaptation of Beetlejuice, "Brinkadoom", where Beetlejuice and Lydia get stuck in such a place, a "sleepy little town" (pun intended) that vanishes when all its inhabitants fall asleep.
 * There is an example of this in Gummi Bears called "Gummadoon".