Interesting fact:

Disney World, Florida, opened in 1971, long after the original Disneyland in California. Walt was unsettled by the sight of costumed characters having to run through the 'wrong' lands to get to their allotted spots, spoiling the magic at the first site. He came up with an elaborate tunnel system which runs beneath Disney World, and allows actors to put on their costumes and appear in the appropriate land without shattering the illusion.