Disney's Magic Kingdom is the most popular theme park in the world, having attracted some 17.5 million guests in 2012. The vast majority of those visitors are completely unaware that a hidden underground complex lies beneath their feet. Most Disney fans (and Theme Park Tourist readers) will know about the "Utilidor" tunnels that are located underneath the park - but even they may not realize the staggering scale and scope of this subterranean world.

Walt Disney planned to locate many of the roads and utilities at his never-built Experimental Prototype Community of Tomorrow (EPCOT) below ground, to avoid its residents having to deal with typical urban problems such as traffic and smog.

After Walt died, his successors failed to fully deliver on his dream of a futuristic city. But they did incorporate elements of it into the design of Walt Disney World - including the creation of the utilidors at its first theme park. The utilidors were among the first elements of the Magic Kingdom to be constructed, and are actually located at ground level (placing them lower would have caused many issues, due to the water table in the Orlando region). They were covered over using seven million cubic yards of earth that was excavated during the creation of the artifical Seven Seas Lagoon that is located in front of the park.

The underground tunnels span an incredible 392,040 square feet. They span most of the park, with the exception of the part of New Fantasyland that was previously Mickey's Toontown, as this was added as an expansion in 1988. You can get an impression of their scale by looking at the (possibly outdated) map below:

A whole range of infrastructure and support functions are hidden away from guests' eyes in the utilidors. Here are 15 examples of things that Disney conceals so they don't spoil the fantasy world that it has so carefully constructed.

15. The "nerve center"

Image © Disney

Located roughly underneath Cinderella Castle is the Digital Animation Control System, a computer system that monitors almost everything in the park. This includes lighting systems, stage curtains, fire protection systems, security systems and power systems. It also controls and sychronizes the movements of hundreds of audio-animatronic figures that feature in the park's attractions.

14. Cast Members

Legend has it that Walt Disney once spotted a cowboy from Frontierland wandering through Tomorrowland at Disneyland. He was incensed at this breaking of the "reality" of the futuristic land, and this is frequently cited as one of the motivations for the construction of the utilidors. Every day, the thousands of Cast Members that work at the Magic Kingdom park in a dedicated lot around a mile away from the entrance to the utilidors, catching a bus the rest of the way.

13. The Character Zoo

Until 2005, the entire costuming department for the Magic Kingdom was located in the utilidors, housing over 1.2 million outfits and dispensing them to Cast Members. Since then, the department has occupied a large building in the Cast Member parking lot. However, Mickey and the other characters still "live" in the Character Zoo, located underneath Fantasyland.

12. "Pargos"

Naturally, Disney wants to keep the air in the utilidors as clean as possible - and that means keeping gas-powered vehicles to a minimum. Instead, Cast Members and goods can get be ferried around using golf cart-style electric vehicles that are known as "Pargos".

11. Cash

One type of gas-powered vehicle that is allowed into the utilidors is the armored cars that come into pick up the mountains of cash generated by the park every day.