The most common misconception about the utilidors is that they are underground tunnels, a basement beneath the Magic Kingdom. They are not. Central Florida's water table sits too high for excavation -- dig a few feet down and you hit water. So Disney's engineers did something audacious: they built the utilidors at ground level and then constructed the entire Magic Kingdom on top of them. Every street, every shop, every castle that guests experience is actually on the second story. Parts of Fantasyland, including Cinderella Castle, sit at a third-story level. The incline from ground to park is so gradual that visitors never realize they are walking uphill. The soil used to raise the park came from the excavation of what is now the Seven Seas Lagoon, the body of water that separates the Magic Kingdom from the Transportation and Ticket Center.

The utilidor floor plan forms a large circle with a path running down the middle. Tunnel walls are color-coded so cast members can quickly determine which section of the park lies overhead. The main entrance sits behind Fantasyland, where cast members arrive by Disney Transport bus from the West Clock parking lot near Disney University. From there, they can reach any area of the park without ever setting foot on a guest-facing walkway. Unmarked doors throughout the Magic Kingdom provide direct access from shops, restaurants, and attractions down into the tunnels. Guests are not allowed in the utilidors unless they purchase the "Keys to the Kingdom" tour -- one of Disney's most popular behind-the-scenes experiences.

The utilidors house virtually every support function the park needs. Trash disappears through an automated vacuum collection system: custodians dump waste into processors throughout the park, and pneumatic tubes shoot it to a central location for compression and transfer to landfill or recycling. The Digital Animation Control Systems -- the park's master computer network -- is monitored from control rooms in the tunnels, overseeing everything from Audio-Animatronic figures to sound systems, parade timing to fire prevention, security cameras to cash registers. Delivery trucks unload into the utilidors rather than driving through themed areas; merchandise and supplies are stored in underground warehouses until needed. The park's cooking and prep kitchens are down here too, sending food up to restaurants above.

For decades, the utilidors housed the park's costuming department -- and it was enormous. Over 1.2 million costumes were stored beneath the Magic Kingdom, making it the largest operating wardrobe department in the world. Every cast member, from the person selling popcorn on Main Street to the Audio-Animatronic figures on Pirates of the Caribbean, was outfitted from this subterranean wardrobe. In 2005, Disney moved the bulk of the costuming operation to a larger facility at the West Clock parking lot, keeping only the costumed character wardrobes in the utilidors. But the scale of the original operation hints at the sheer logistical complexity hidden beneath the park's surface: thousands of people costumed daily, every outfit themed to a specific land, every detail managed so that no cast member ever appears out of place.

The utilidors are, in effect, a functioning city beneath a theme park. Separate locker rooms for men and women line the corridors. Cast member cafeterias serve meals around the clock. A branch of Partners Federal Credit Union operates down here, alongside rehearsal rooms and administrative offices. Two medical carts from Reedy Creek Emergency Medical Services stand ready to deploy through the tunnels to reach any medical emergency in the park above. Smaller utilidor systems exist beneath the central section of Epcot's Future World -- under Spaceship Earth and the former Innoventions area -- and a compact version runs through Disneyland's Tomorrowland in California. But the Magic Kingdom system remains the largest and most elaborate, a hidden infrastructure so complete that the park above it can maintain its illusion without interruption, every day, year after year.