Disney UTILIDOR System
In Disney theme parks, the utilidor system is a system of some of the world's largest utility tunnels, mainly for Walt Disney World's Magic Kingdom in Florida.
The utilidors, short for utility corridors, are a part of Disney's "backstage" (behind-the-scenes) area. They allow Disney employees ("cast members") to perform park support operations, such as trash removal, and for costumed characters to quickly reach their destinations on the surface out of the sight of guests to avoid ruining the illusion that is being created.
These tunnels were first built for Magic Kingdom. Smaller utilidor systems are built under the central section of Epcot's Future World, primarily beneath Spaceship Earth and Innoventions, and formerly at Pleasure Island.
Disneyland, in California, also has a small utilidor system running throughout Tomorrowland.
Sauce: https://en.wikipedia.org/wiki/Disney_utilidor_system
I remember some years ago, there was a scandal when young people said that they had been kidnapped at Disney World, and held down in the Tunnels. They described that they were held in many rooms down there.
So many people came forward that Disney closed down the Tunnels, but left the outermost room open. Disney invited the Press to look at the remaining open room at the opening of the tunnels, to show that there's nothing there.
Will see if I can digg up those Florida newspaper articles.https://www.youtube.com/watch?v=zXyCB79gmKM