In the late 1960s, Disney acquired 25,000 acres of barren swampland in Florida. Over the next four decades, the company transformed it into the world's leading theme park resort.

It wasn't an easy job. Miles and miles of drainage canals were built, millions of trees, shrubs and other plants were introduced and entire lakes were excavated. Four enormous theme parks were eventually built, along with two water parks, a shopping and entertainment district and dozens of huge hotels.

We're all familiar with images of the finished theme parks. But what did Walt Disney World's attractions look like while they were being constructed? We've dug out a series of stunning photographs that show how the enormous structures were put together, and put them into a single article that shows how 40 years of intense development led us to where we are today.

Magic Kingdom

Walt Disney World's first theme park, the Magic Kingdom, opened in 1971. It is a virtual clone of the original Disneyland in California, but on a larger scale - Disneyland covers 85 acres, whereas the Magic Kingdom sprawls across 107 acres.

To enable Cast Members to move around the park without being seen, a series of tunnels, known as "utilidors", were built underneath the park. To do this, soil excavated from the Seven Seas Lagoon in front of the park was used to build up the level of the park.

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Here's a look at Cinderella Castle as it was being built. The castle stands at 189 feet tall, compared to Sleeping Beauty Castle at Disneyland which is just 77 feet tall. Both castles used "forced perspective" techniques to make them appear larger - as each gets taller, its width gets smaller. No stonework was used to create Cinderella Castle, despite its appearance. The building's shell is made out of fiberglass.

The next few photos show the Rivers of America (a false waterway that winds its way around Frontierland and Liberty Square), as well as the Haunted Mansion and the Hall of Presidents in Liberty Square.

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And here's a look at the finished product...

Space Mountain

Here's a look at one of the first major additions to the Magic Kingdom's line-up: Space Mountain. The ride opened in 1975, and you can see images of both the exterior and interior below.

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Big Thunder Mountain Railroad

In 1980, a second "mountain" opened at the Magic Kingdom. The enormous Big Thunder Mountain required 650 tons of steel, 4,675 tons of "mud" and more than 9,000 gallons of paint to construct.

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Splash Mountain

Splash Mountain joined the Magic Kingdom's line-up in 1992. More than 65 Audio-Animatronic characters populate the attraction, with the concrete flume winding for more than 2,600 feet.

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