There are those who love carnival haunted houses and dark rides, and those who don't. The clackity-clack of the cars running along the track, the musty air with an occasional whiff of cotton-candy or bile, the gaudy plywood forms painted in florescent hues, the air-powered peek-a-BOO! pop-up ghoulies – all of these things inspire either fear and loathing or a giddy sense of escape, depending on the stars one was born under, it seems.

Walt Disney didn't love the grimy atmosphere of the carnival, but he did love dark rides. The storied mogul took his favorite yarns and fairy tales (grim as the original stories often were), made them into feature films loved around the globe, and then turned those films into dark rides in his personal vision for what a carnival could be like – should be like. That vision eventually became Disneyland, and Disney's dark rides remain among the most popular themed attractions in the world to this day. Just try to ride Disneyland's "Peter Pan's Flight" around two in the afternoon, and you'll understand. Yes, they may be called "kiddie" rides. But who doesn't want to believe they're still a kid at heart?

Disney's darkest dark ride, the Haunted Mansion, finally opened to the public on August 9, 1969, though Walt had started formal development of the attraction in the early 1950s, with some design sketches and concepts for the haunted house created long before Disneyland even opened its gates on July 17, 1955. But Disney's ambitions to create a truly mystifying attraction (along with worthy distractions, such as the development and creation of famous exhibits for the 1964-1965 World's Fair in New York) carried the design phase of the Haunted Mansion attraction well into the later part of the 1960s. After their work for the World's Fair (for which Disney's exceptional team of hand-picked WED "Imagineers" perfected their robotic actors, known as "Audio-Animatronics"), Disney assigned some of his strongest talent to get back to work on Disneyland. Those designers would go on to complete the world's finest example of a robotic themed attraction (the Pirates of the Caribbean), and after that, the world's greatest haunted dark ride in the hearts of legions of scare lovers, the Haunted Mansion.

Of course, those same designers might not agree with that assessment. Many of the Haunted Mansion's key developers disagreed with the direction the project took after the death of Walt Disney in December 1966, nearly three years before the attraction would be completed. In fact, to this day, some of the designers are unhappy with the result of their efforts. The Haunted Mansion's long development was rife with repeatedly discarded story concepts, disagreement on the types of scenes and effects to be used, conflicts over how many viewers should be carted through the attraction per hour – even as basic an idea as whether the attraction should be scary or not. Egos were bruised, tempers flared, and at the end of the day, it just seemed that there were "too many cooks in the kitchen," as Imagineer Marc Davis would repeatedly recall. Most of the original design team members look back at their individual tasks and work on the Haunted Mansion with pride, but scratch their heads at whether or not to call the overall finished attraction a success. Yet many Disney theme park guests call the Haunted Mansion their favorite attraction, and it commands an army of die hard fans.

The timeless nature of Disney's mythic attractions such as Pirates or the Haunted Mansion plays a role in this continuing popularity. The Haunted Mansion, an attraction that Walt had planned to build in the early 1950s, is now nearly five decades old – but what's forty or fifty years? Consider 250 years, which is the age of some of the most confounding magic inside the Haunted Mansion. Visitors experience entertainment technology here that spans four centuries. The "magic lantern" was used to project illusions on walls as early as the late 1700s. "Pepper's Ghost," a stage trick involving reflections, was used to create living, transparent ghosts in the 1800s. Disney's own space-age robotic technology came to life in the mid-1900s, and digital projection and computer-controlled effects have just entered prime-time this century – and all of these techniques are used with great impact throughout the Haunted Mansion. It utilizes the best special effects techniques from the broad history of modern live entertainment, so it's no surprise that it still appeals to anyone who loves being amazed and impressed by great feats of imagination.

A trip through the Haunted Mansion leaves the typical visitor slack-jawed, whether he or she is a dark ride aficionado or not. The sheer scope of the ride is mystifying, especially since the guest is led to believe that the entire ride occurs in the relatively small visible facade of a late nineteenth-century plantation manor that you enter to begin your tour. But hidden elevators swiftly move visitors underground, and the massive ride itself occurs in an enormous warehouse beyond the visible berm that separates Disneyland park from the outside world. While the Walt Disney World version of the attraction has a larger, more imposing facade, the secret scale of the attraction is no less amazing.

Once inside the doorway, guests will experience a haunting tour, eerie atmosphere, and obsessive attention to detail everywhere. Even the gleaming stanchions used to hold the chains that direct the queue to board the carriages are unique brass bat-gargoyles, custom-made for the ride. Crystal chandeliers are outfitted with thick, draping cobwebs. Bronze gargoyles hold flickering candles in their clawed hands. Detail was so important to Walt Disney that WED Enterprises even hired a master woodcrafter from Cuba specifically to sculpt the enormous number of architectural details scattered throughout the Haunted Mansion. Suffice to say, there are plenty of silly sight gags and breathtaking illusions to go around. A gallery stretches before your eyes. Marble busts stare you down, and follow your every move with their malevolent glare. Restless spirits materialize, and in one stunning set piece, you can watch them dance in and out of sight, disappearing and reappearing as you look right through them.

The engaging details can't be contained to the interior of the mansion, however. Upon reaching the attic, with nowhere else to go, riders are thrown from a window into the private graveyard, where in a cacophony of crazy music and singing statues, the graves open to release their occupants, all of whom have "come out to socialize," as the ride's theme song insists. Behind a glowing veil of fog, dead socialites share a sip of tea with each other, while an Egyptian mummy murmurs in the background. An executioner sings a duet with his victim, a decapitated knight (who holds his singing head under his arm). And finally, as you are about to escape through a crypt, a trio of hitchhiking ghosts tries to join you by materializing aboard your "Doom Buggy." In fact, the sheer amount of details even gave the ride's designers pause – at least until they caught up with Walt Disney's vision, which entailed leaving the guest ready for a repeat performance. WED Imagineer X. Atencio, who developed concepts and wrote the script and song for the Haunted Mansion, recalls a conversation he had with Walt about the Pirates and Haunted Mansion attractions, which were packed with scenes, sounds and conversations surrounding the ride conveyances, which seemed to move past the scenes too quickly for the guests to catch all of the goings-on. "I said, Walt, I apologize, but you can't understand what they're saying. Then he said 'X, it's like a cocktail party. You tune in on this conversation, then you tune in on that. Each time they come in, they'll hear something new.'"

Despite the rich centuries-old technology, the attraction still appeals to today's sophisticated theme park attendees. Many of Disney's Imagineers, who designed and built the Haunted Mansion, are forefathers, in a sense, of today's wired generation. There can be no doubt that many of those Imagineers would feel at home in today's "maker" culture, were they part of this generation. You had arguably the world's finest animator designing the gags for the ride in Marc Davis (the creator of Tinker Bell from Peter Pan and Maleficent from Sleeping Beauty), and then there's the genius of tinkering duo Rolly Crump and Yale Gracey, who would lock themselves in a warehouse and engineer mechanical illusions so hair-raising that the cleaning crews would refuse to go into the room. In the early days of the Haunted Mansion's development, WED Enterprises was composed of an intimate group of inventors, dreamers, and mad scientists, forging their way without precedent. Today's geek culture is reflected in that set of circumstances.