Madwoman in the Attic



"Dr. Hibbert: But what to do with poor Hugo? Too crazy for Boys Town, too much of a boy for Crazy Town. The child was an outcast. So, we did the only humane thing. Homer: We chained Hugo up in the attic like an animal and fed him a bucket of fish heads once a week."

"--The Simpsons"

This is when a character with mental problems, and often some physical deformity, is locked away because she will never fit into society, usually either in the attic or in the basement, and often by a Corrupt Hick. The smarter ones will have a secret system of peepholes throughout the house. They also tend to be inbred.

There are two basic plotlines for this type of character:
 * 1) The main character is an outsider, wondering what kind of bizarre secret the Corrupt Hicks are keeping. These characters tend to be Dragon-type enemies with little personality of their own, or they're The Grotesque, sympathetic victims. When done well, this can be an effective scare because it so aptly encapsulates the frightening insularity of the Town with a Dark Secret.
 * 2) The main characters have just moved into a new house, and unbeknownst to them, are being watched by one of these whose caretakers have died. These are scary because of how they personify the fears of buying a new house: that your house has some hideous aspect that you haven't seen, but can see you.

This trope is named for the landmark work of feminist literary criticism by Sandra Gilbert and Susan Gubar, referring to in Charlotte Brontë's Jane Eyre. The analysis indicates that this trope first popularly appeared, in all places, in Victorian women's literature, where depicting some women as crazy people was an easy way to make female villains with whom readers would be unlikely to sympathize. Obviously, this plan was not a complete success.

Usually either Ax Crazy or The Grotesque. Compare Man in the Iron Mask.

Anime & Manga

 * from Sakura Gari, who has been locked in an old house for nine years
 * Hisoka Kurosaki from Yami no Matsuei is locked away by his parents because of his empathic powers.
 * At least two cases from Detective Conan have people trapped in attics and becoming unstable.
 * One featured a gifted writer, hiding in the attic after committing a murder over a decade ago. He was very sane indeed, just rather confused/fascinated over a cellphone.
 * from Mermaid Saga.

Comic Books

 * One of Sabretooth's possible backstories shows him as a child chained up in the basement with a dog dish, his father periodically coming down to yank out his claws and teeth.
 * The mini-series Freaks Of The Heartland is told from the perspective of the normal brother of one of the several Grotesques who've been locked away since the small town's Bizarre Baby Boom years ago.
 * At one point, Dv8, Gen13's Evil Counterpart, meets an even eviller team called Twist. One of Twist's Kick the Dog moments is when one of them shows Dv8's Evo a cellar under their base crammed full of Body Horrors mutated by the same Phlebotinum that gave the others powers, and tries to get him to have sex with her in front of them.
 * Horridus from The Savage Dragon and Freak Force is a reptilian-looking Half-Human Hybrid whose parents kept her chained up in the basement. But TSD being a comic book where the main hero is a green guy with a fin on his head, Horridus didn't have that much trouble integrating with society.

Film

 * In Harold and Kumar Escape Guantanamo Bay. The titular duo wind up in Alabama, and are befriended by an Ugly Guy, Hot Wife, who happen to be siblings. Their cycloptic, freaky, inbred son is kept in the basement when company comes over. They weren't Corrupt Hicks though, they were nice people, they just happened to follow Brother-Sister Incest and have The Grotesque as a child.
 * Dario Argento's Phenomena has one of these.
 * Karl Childers in Sling Blade spends his childhood as one of these. The long-term hospitalization following his murder of his mother may also qualify.
 * Sloth from The Goonies. A sympathetic example of Type 1.
 * The title creatures of The People Under the Stairs. Tweaked, however, in that the imprisoned things weren't born that way, but were kidnapped as young children and imprisoned under horrid conditions that caused their degeneration.
 * In The Unearthly (which famously includes Tor Johnson saying "Time for go to bed") the Mad Scientist played by John Carradine has a bunch of degenerate caveman things in the basement. Crow thinks they look like Ian Anderson on the cover of Aqualung.
 * The Merrye relatives in the basement in Spider Baby.
 * The titular character of Powder.
 * The titular freak in Castle Freak has been locked in a dungeon by his mother since his early childhood, fed scraps and beaten regularly, among other things. When she dies he is forced to break out or starve. As you'd expect he's not all there. Definitely qualifies as a Grotesque.
 * The first Basket Case film although Belial's titular "attic" is portable and he doesn't seem to complain about staying hidden. Furthermore he's even said to prefer to keep to himself in the sequels.
 * If mobile "attics" count, then Blaster from Mad Max Beyond Thunderdome might be a borderline case. He lives behind an armored mask and never associates with anyone except as Master's transport, and when the mask comes off, it's revealed that he.
 * Nick Frost apparently plays one of these in Don't, but really, it's hard to tell.
 * The Orphanage does this with the disfigured (but not disabled) Tomas by putting him in a mask and keeping him in a secret room.
 * But in something of a subversion he's still allowed out, and to play with other children. The whole matter of keeping him in that room seemed to be a quirk of his overprotective mother, more than anything else.
 * There's a movie called The Gay Bed and Breakfast of Terror. The crazy Jesus freak mother is keeping her mutant son Manfred (who ) locked up in the attic until she wants him to kill someone.
 * This is what happens to the two novices in The Hideout after one of them killed her Mother Superior and other two old women to prove her boyfriend she loved him, and one of the women was the guy's mother, letting him free to inherit. They didn't see anything wrong with any of that, though.
 * The Val Lewton classic I Walked With A Zombie (based on Jane Eyre) may feature one of these. Like many of the films Lewton produced, the reality is open to interpretation.
 * Invoked in Paranoiac, where Simon thinks
 * In the Hammer Horror The Brides of Dracula, Baron Meinster is introduced this way: his mother keeps his locked up in a wing of the castle. Her stated reason is that he is unwell. He claims that it's because she's trying to cheat him out of his inheritance. It turns out that he's a vampire (the clue is in the movie title) and she's trying to keep him locked up, but doesn't have the heart to kill him.
 * Saul Femm from The Old Dark House (1932), though not incredibly deformed, is a raging madman with a taste for arson and is thus kept locked in his room by the rest of the family with the help of a mute and deformed butler.
 * In the Black Christmas remake, after murdering his father, Billy's mother and her lover keep Billy locked in the attic, where he goes steadily more insane before finally snapping one Christmas and murdering them (as well as mutilating his sister/daughter Agnes).
 * The Penguin in Batman Returns spends his early years as this, before his parents get rid of him by throwing him to the river.
 * The opening narration for Kiss the Girls describes a self-inflicted version of this: Casanova moves into the attic of the house where his "first love" lives.
 * Larry Blamire's Dark and Stormy Night has Thessaly
 * The mother in The Curse, loosely based on The Color out of Space becomes one of these late in the film.
 * Zelda of Pet Sematary.
 * The Beast in the Cellar.

Literature

 * Arthur "Boo" Radley from To Kill a Mockingbird.
 * In the short story, "The Ones Who Walk Away from Omelas" by Ursula K. Le Guin, a filthy, malnourished little child of indeterminate gender is locked in a windowless room and treated as an animal for the vague good of the community.
 * Mr. Edward Rochester keeps his violently insane wife Bertha locked in the attic of Thornfield in Jane Eyre.
 * Jean Rhys' Wide Sargasso Sea examines this example (yes, this one -- same woman) more deeply, giving a possible Backstory of (the literal) Bertha in The Attic.
 * She also appears in The Eyre Affair, in which she inadvertently shows the heroine how to defeat the Big Bad.
 * The Yellow Wallpaper: the main character is bedridden with some illness, and locked up in a room with ugly, confusing wallpaper. She goes crazy as a result. It's primarily a critique on the medicine of the time and the then-disturbingly common practice of keeping "ill" women stuck in a small room with nothing to stimulate them (this was actually done to the author and she nearly went insane as a result). It's also a very creepy little psychological horror story.
 * H.P. Lovecraft was fond of this one: he contributed multiple examples.
 * The Outsider, who is also in an Ontological Mystery.
 * The Dunwich Horror, a Half-Human Hybrid kept in the attic by a Corrupt Hick.
 * This particular example eventually grew so large that the man had to tear down the inside walls, nail the windows shut, and move into one a shed. Also, it's implied that the attic dweller called all the shots.
 * The Shadow Over Innsmouth: The narrator makes reference to a relative (who has been slowly transforming into a fish man) locked away in an asylum. It's also noted that a few of the Innsmouth people have gotten so deformed that they don't go outside anymore.
 * The De Le Poer family from The Rats in the Walls kept degenerate people as livestock in the basement.
 * The Gardner family in The Colour Out of Space have an elderly female relative who goes crazy as a result of exposure to the titular Colour, and is locked in the attic, where she becomes even more strange...
 * It was Nabby Gardner, Nahum Gardner's wife, that this happened to. Also Thaddeus, one of the sons.
 * A debatable example, the degenerate inbred Martense Family in The Lurking Fear. They live in a series of tunnels underneath their ancestral manner, linking to the graveyard.
 * Rhoby Harris in The Shunned House. After the presence haunting the titular house attacks her, her protests are dismissed as just another symptom of her insanity.
 * The Phantom of the Opera is an early example, and also interesting because he exiled himself.
 * The Hunchback of Notre Dame is a sympathetic example.
 * In Richard Matheson's short story Born of Man and Woman, a deformed child is kept chained in the basement by its parents.
 * In the Doctor Who Eighth Doctor Adventures novel Vanishing Point, this trope is reconstructed with a woman keeping a number of deformed and disabled people away from society. But in a bit of a twist, she's quite nice to them, treating them almost like family, and refers to them affectionately as "mooncalves". The story takes place in a Dystopia where they wouldn't be safe anywhere else.
 * In The Blue Angel, the Lighter and Fluffier variant continues. The Ambiguously Human Alternate Reality Doctor's Beloved Smother is a mermaid, and he has two hearts, no navel, and several other general idiosyncrasies. He's also delusional, although it's not clear when that developed. At any rate, as his mother considered both him and herself too weird for society, he grew up as a shut-in. It might not have done his mental health any favors, but his mother meant well.
 * In The Shuttered Room, a woman returns to her childhood home where her insane sister has been imprisoned by an elderly aunt.
 * Used in Wolf in the Fold from the Hawk And Fisher series.
 * Carly from F. Paul Wilson's Faces: The existence of others like her is implied in this and other Adversary Cycle stories.
 * In David Eddings' The Elenium series, the tower of a Gothic Horror castle becomes the holding place for a noblewoman driven mad by Demonic Possession. Her last remaining loyal servant, unable to listen to her scream any more, finally slips poison into her food to Shoot the Dog, and then becomes The Atoner and joins an order of monks.
 * The novel Flowers In The Attic is written from the point of view of children locked away in this manner, to hide their existence from their grandfather, who would disinherit their mother (his daughter) for having married and had children by . The grandmother is very much in on this (delivers meals, etc.), is rather abusive, and as Mom decides she has better things to do with her time than spend it with the kids, becomes the primary outside contact the kids have.
 * There is a book, Woman in the Wall, where an exceptionally shy girl with a phobia of wide-open spaces did this to herself, choosing to live inside the walls of her house instead of starting school. Then her family stopped seeing her or hearing her talk, though she would eat at night and fix things and sew.
 * In Francis Hodgson Bernett's The Secret Garden, Mary's uncle keeps his son and Mary's cousin, a bedridden hunchback and sickly child named Colin, hidden away in the house for fear that he will not be able to survive in normal society, and shuns him because of the boy's resemblance to his dead mother.
 * There's a story that was filmed for the Twilight Zone called The Howling Man. In it, the protagonist visits a European monastery in the early 1930s and hears horrible screams in the middle of the night. He finds the man imprisoned and frees him. Turns out that was Satan imprisoned there to prevent him from bringing strife to the world, and well, given the time period, you can guess what happens next.
 * In The Magician's Nephew, Digory and Polly, being familiar with this trope, consider that Uncle Andrew might have a mad wife hidden in his attic. He's actually experimenting with the rings that are among the Mac Guffins of the series.
 * The creature in Still Life with Crows is one of these kept in a cave who found his way out. Also Subverted in that he started out as a normal child (and apparently a very intelligent one) who was twisted by being forced to live in the cave (his mother gave birth out of wedlock, and her father forced this whole thing on her).
 * Happens twice in Harry Potter- to Harry himself in the first book, and . Subverted with Harry, though, as he was locked in a cupboard under a stairway, but was allowed outside unless he showed signs of magic. He was then freed when all the letters came from Hogwarts, but only because his aunt and uncle thought the letters would stop coming if he slept in a different part of the house. And then he got locked in there anyway, and food was passed to him through a cat flap.
 * As for  this was played semi-straight. She went mad   and was locked up after  . Everybody outside the family (the ones who knew about her existence, anyway) figured her mother had locked her up for being a Squib (a wizard with no magical ability), which was a bad thing to be during  . Which, in the present in the novels, is still a bad thing.
 * Chance the Gardener in Being There was isolated to the Old Man's house all of his life due to his mental retardation and no one but the maids who worked in the house knew he existed. And it's possible he's the Old Man's illegitimate son to boot. The story gets underway once the Old Man dies and he is turned out of the house by the lawyers who came to close the estate. He's a nice, well-spoken person, however (partially due to his being allowed to watch television, giving him some idea of proper behavior and speech), and winds up becoming a Parody Sue when he encounters people who have no idea what he really is.
 * The novel The Cellar is about a woman who keeps horrific rat-men in her old house.
 * Paul Auster's City of Glass features a character that was brought up at home in complete isolation as part of a crackpot linguistic experiment by his father. At the time of the story, he has been recovered and mostly rehabilitated - he has learned to speak - but is still quite disconcerting.
 * Subverted by The Adventure of the Paradol Chamber, a Sherlock Holmes pastiche written by June Thomson. A woman who has befriended a young nobleman hires Holmes to investigate because she's afraid that his servants have imprisoned him in his own house. As it turns out, not only do the servants have a very good reason for locking him up, the nobleman actually wanted to be imprisoned in the first place, since
 * Another subversion comes from The Adventure of the Blanched Soldier, written by Sir Arthur Conan Doyle himself, that is much along these same lines. A soldier who made friends with another younger soldier in the Boer War hires Holmes when he thinks the younger soldier's parents are keeping him imprisoned on their family estate. It turns out
 * Then there's "The Yellow Face," in which the suspected Madwoman in the Attic in fact turns out to be
 * The protagonist in Neil Gaiman's short story "Forbidden Brides of the Faceless Slaves in the Nameless House of the Night of Dread Desire" has an Aunt Agatha chained in his attic. This has no bearing on the plot, it's just one of the things that establish that he lives in a world of Gothic/adventure/fantasy/horror fiction clichés. A character in the story he's writing is also mentioned to have (had) a "hopelessly insane" wife whom he claimed to be dead. Well, he is writing a realistic, slice of life story based on the world he's living in.
 * The horror novel Others has a whole wing of a nursing home filled with Freaks in the Attic. Some of them are nice people who just have a physical deformity of varying severity. The titular Others, though, either because of their imprisonment, or what the director of the home has been doing to them, or just madness, are true monsters.
 * Both Charlie Angelfield and his father, George, in The Thirteenth Tale go mad after the death of their loved ones, and enter into a sort of self inflicted imprisonment where they lock themselves in their rooms for extended periods of time.
 * Hortensia from Isabel Allende's "Cuentos de Eva Luna" (Takes of Eva Luna).

Live-Action TV

 * Parodied on The League of Gentlemen with David, inbred son of corrupt hicks Edward and Tubbs Tattsyrup. They keep him in the attic.
 * George Cranleigh in the Doctor Who serial "Black Orchid".
 * Control and Redvers Fenn-Cooper from another Doctor Who story, "Ghost Light".
 * Also showed up in the NewWho episode "The Idiot's Lantern," in which a family keeps Grandma locked in her bedroom  Note that this episode was written by the same man who played the above David Tattsyrup.
 * Played with in The Twilight Zone episode "The Howling Man". The title character is locked in a monastery cell and spends a lot of time howling mournfully. The protagonist of the story thinks he's crazy, but after the protagonist releases him
 * The X-Files had an episode called "Home" that dealt with several backwoods-horror tropes, including this one.
 * And of course also "Post Modern Promehtheus", which was a deliberate deconstruction and Affectionate Parody of Frankenstein/deformed monster.
 * The Babylon 5 episode "Grey 17 is Missing" featured a bizarre cult that had taken over one of the decks of the titular space station, hidden it on the blueprints and computer schematics, isolated it so no one else could enter...and then locked up themselves on that level with a ravenous alien monster which would periodically eat one of the cult members and thus make them one with the universe via a perfect death.
 * Desperate Housewives did it with Caleb.
 * The MacGyver episode "The Secret of Parker House" had one of these.
 * Supernatural has this as the twist in
 * Which, par for the course, was played quite disturbingly. Once again, Supernatural takes the trope, and fills it to the brim with Nightmare Fuel.
 * In one of the 1990s Outer Limits various Science Is Bad episodes, a couple considering genetic enhancement for their unborn child learn that their neighbors' supposedly dead son is actually an Ax Crazy basement-dwelling monster as a result of genetic engineering Gone Horribly Wrong.
 * in the Midsomer Murders episode "Judgement Day".
 * Smallville has some parents lock their boy in the basement and never let him see the sun, because.
 * Done with the half-breed Scorpius in Farscape. The episode "Incubator" reveals that was raised on a Scarran ship in a single room and his only visitor was his "nanny," Tauza- until, of course, Scorpius managed to escape. Quite worryingly, it's implied that Scorpius' mother was imprisoned in the same cell in a pretty similar fashion; according to Tauza, her impregnation at the hands of one of the guards drove her insane- making her a quite literal case of Madwoman in the Attic.
 * in one episode of Sanctuary, the one with the young autistic boy who draws monsters, a missing twin brother, their dead father, and the room under the floor, which has shackles welded to one wall.
 * CSI had a rather sweet young woman who happened to have a serious case of hypertrichosis and lived in a secret room in her brother's (also a sufferer, but to a lesser extent) house. She wasn't locked up, but she'd been kept in the house in daylight hours for many years and always retreated to her room when visitors came, so no one knew she was there until after her brother's murder.
 * In the Made for TV Movie Bad Ronald, young Ronald's mother locks him up and hides him so the police can't arrest him for a murder he committed. When she dies, he remains in the house, and a new family moves in.
 * On American Horror Story, Constance kept her disfigured son, Beauregard, in the attic. CPS was going to take him away but she had Larry kill him first, claiming he died on natural causes.

Music

 * The Alice Cooper song "Former Lee Warmer" is sung from the perspective of a man who keeps his mute and apparently insane brother locked up in his attic.
 * Aphex Twin's Rubber Johnny video features a deformed wheelchair-bound kid in a dark basement.

Myth and Legend

 * If not the Ur Example, then certainly the Knossos Example would be the Minotaur. When Minos decided to keep a bull he had been sent by Poseidon to sacrifice to him, Poseidon made Minos's queen fall in love with the bull and conceive a child with it. To hide the resulting hybrid monster, the king commissioned Daedalus [Icarus' papa, and the man who helped the queen consumate her unnatural love] to build an elaborate labyrinth under the city from which no one could escape.
 * The Monster of Glamis, a deformed child supposedly born to the Bowes-Lyon family and bricked up in Glamis Castle.
 * Some versions of the Jersey Devil's Backstory would qualify, depending on how soon after its birth the creature escapes into the woods.

Tabletop Games

 * In the third edition Ravenloft products from Arthaus, the role of half-orcs is instead given to 'calibans': a PC race of Berthas in the Attic, usually born to human mothers who'd been exposed to black magic or curses while pregnant.
 * Saul Whateley, resident of Gomorra in Deadlands: The Weird West, was locked in the attic by his Big Screwed-Up Family. His insane rantings are still loud enough to keep others in town awake at night. He's useless in a fight, though he might be seen as a sympathetic villain.
 * Genestealer Hybrids in Warhammer 40000 tend to possess obvious physical deformities such as greyish skin or multiple limbs until the third or fourth generation, and as such have to be hidden from the rest of society, either by their doting parents or the other members of the Genestealer Cult. A favored haunt is a hive city's Underhive, the derelict, lawless lower levels of the Imperium's arcologies.
 * Ogre Gorgers from Warhammer Fantasy Battle are cast out of a society of Big Eaters for the crime of being born too scrawny. Thrown into the labyrinthine, Warpstone-laced tunnels beneath an ogre settlement, if the Gorger survives the isolation and Warpstone will quickly mutate it into an insane, pallid, degenerate, and above all else ravenous monster.

Video Games

 * The Interactive Fiction game Anchorhead features William, an inbred boy that has been touched by Eldritch Abominations.
 * As does Adam Cadre's Shrapnel.
 * In Five Days a Stranger, the deformed, mentally challenged son of Sir Roderick Defoe is kept in a secret room of the house.
 * In Call of Cthulhu: Dark Corners of the Earth, a woman in the  is kept in the attic as she falls to The Corruption. The husband is just trying to keep his family safe, though.
 * If you know about Lovecaft's story the game is based on, it's clear that the "woman"
 * , in a combination of both Type 1 & 2.
 * Appears in the original Clock Tower.
 * In the form of
 * The Lighter, Softer, Pedantically Scottish and less successful remake of The Seventh Guest, Clandestiny, features the Monster Child MacPhiles, who not only is a fright to behold but would haunt her familial captors with beautiful singing, just to remind them what scoundrels they are for locking her away.
 * The Touhou Project's uberpowered little vampire, Flandre Scarlet, has lived in the basement of the Scarlet Devil Mansion for the past 495 years at her (slightly) older sister Remilia's behest. Since Flandre has a child's naivety, emotional instability that borders on insanity, and happens to have the power to almost effortlessly destroy anything ("I went 'kyu' and it went boom"), this is probably more of a safety measure than anything else, and official sources suggest that Flandre is okay with the arrangement. Fan portrayals play the situation for horror or drama as needed, and can vary from a sympathetic Flandre being locked away by her domineering older sister to a secretly-heartbroken Remilia forced to cage a psychotically destructive Flan for her own good.
 * Kinzo Ushiromiya in Umineko no Naku Koro ni locked himself in his little mini-apartment at the top of the Kuwadorian mansion in Rokkenjima and refuses to come out. He's certainly crazy enough to qualify.
 * Somewhat reversed in Fallout 3: Point Lookout with Kenny, who ran away after his deformed parents hid him in their basement for lacking the right "marks."
 * Double Switch: It is revealed in the game that.
 * In Resident Evil Code Veronica, a monster codenamed Nosferatu, who is actually the mutated Alexander Ashford, is imprisoned in the Antarctic Base. In the remake of Resident Evil 1, the grotesquely deformed and chained Lisa Trevor wanders the basement and backwoods of the Spencer estate.
 * Somewhat reversed in Fallout 3: Point Lookout with Kenny, who ran away after his deformed parents hid him in their basement for lacking the right "marks."
 * Double Switch: It is revealed in the game that.
 * In Resident Evil Code Veronica, a monster codenamed Nosferatu, who is actually the mutated Alexander Ashford, is imprisoned in the Antarctic Base. In the remake of Resident Evil 1, the grotesquely deformed and chained Lisa Trevor wanders the basement and backwoods of the Spencer estate.

Western Animation

 * Parodied in a Halloween Episode of The Simpsons, with Bart's Evil Twin, Hugo, locked up in the attic. The Twist Ending was that Bart was the Evil Twin, so Hugo was allowed to go free (even though he was clearly insane - then again, you'd be insane too, if in his shoes) and Bart is locked up in his place.
 * The Animaniacs are an example that got loose. And where would we be now without them, hmm? United States, Canada, Mexico Panama....
 * Implied that the Morgendorfers in Daria had moved into a house that had one of these. Daria actually picked the room with the padded walls. Course, we don't get to see that.
 * In the South Park episode "Marjorine", Butters is selected to fake his death. When he returns home, his parents chain him up in the basement believing he is a Damaged Soul and kill a woman so he can feed. Due to Negative Continuity, he is out in the next episode.
 * The Oblongs do this to Granny. Sort of. Their son isn't even aware Granny is still alive.

Real Life

 * Actually happened (hopefully not anymore); A program on old houses featured a new homeowner doing research into a recently-purchased 19th century house, trying to determine the purpose of a second-story room with iron bars on the windows, a metal floor with welded metal loops for attaching chains, and a door that locks from the outside. While researching at the library, an old woman overheard him describing the room, tapped him on the shoulder, and gently explained to him, "You have a Disappointments Room," where children with developmental disorders were kept by families that didn't know what else to do, and didn't want their secret known. Further research turned up the former owner's family gravestone at the local cemetery; there was one name, a girl's, and a set of dates indicating death at a young age, that did not correspond to any of the family members listed in the town's archives.
 * The veracity of this is questionable. There are apparently no other accounts of "disappointments rooms", and many problems with the story. A disabled toddler needed chains to be controlled? Loud clanking chains weren't counterproductive to the goal of keeping her a secret? The massive construction project required to build it in the first place didn't raise neighbors' eyebrows? They were determined to keep her very existence secret, but had no problem revealing it posthumously by giving her a public burial? Unless there are better corroborating sources than the one highly speculative account, I think it's safe to classify this as an urban legend.
 * Someone familiar with the actions and behaviors of children with learning disorders/other psychological and mental problems points out that strong restraints or physical force are often necessary to maintain such children's behavior. As for the clanking chains etc., neighbors might have noticed without acknowledging noticing.
 * A few supposed 'feral children' were locked up and isolated from human contact at a very young age, possibly because they were already a bit odd. The abuse doesn't exactly help.
 * Then there is the tale of "Genie" Genie spent her entire childhood locked-up and tied to a potty after her father (who wasn't the pillar of sanity himself) learned she was "mildly retarded" and blew it out of proportion. When she was rescued, it was discovered that she could not speak and she had a distinct "bunny" walk.
 * Kaspar Hauser claimed to have been one of these.
 * The legend of the Monster of Glamis, which seems to have at least some factual basis.
 * John Langdon Down (of Down Syndrome fame) advised against this in his writings, arguing that institutionalization was more humane, and that isolation and lack of education tended to make mental defects worse.
 * Supposedly the Lemp Family--founders of the now-defunct Lemp brewery--had a a son who was born deformed. He was known as the Monkey Boy, and kept locked in a cage suspended ten feet off the ground, deep in the caverns under the brewery. The cage is still there.
 * At points in the history of treating mental illnesses and syndromes, this has been the humane option--for reasons varying from the then-current State of the Art ideas of mental illness to modern, enlightened laws that make it impossible to permanently institutionalize many of those who are only functional in an institution. It mostly takes being disabled to the point of not being legally responsible for yourself, or having killed a few people the last time you stopped being functional.
 * Patrick Henry kept his wife in their Viriginia basement for the last four years of her life, feeling it was more humane than the public hospital. Given that she would have had a windowless cell with chains and a chamber pot a the aforementioned hospital, he was probably correct.