Walt Disney had grand ambitions for Disneyland. He wanted to do much more than simply entertain - instead, he wanted to educate guests and influence the future development of the world itself. The early years of the park were marked by frantic expansion and rapid innovation, with Disney's Imagineers inventing new ride systems and special effects at a furious pace. Things have calmed down significantly since then, and some fans have accused Disney of resting on its laurels by focusing on attractions inspired by its selection of animated movies rather than continuing to push the boundaries. But there are still examples from recent years of attractions that broke new ground. Let's take a look at 20 of the most revolutionary Disney attractions ever built, focusing on what made them special and the impact that they've had on future developments both within and outside the theme park industry.

20. Star Tours / Star Tours: The Adventures Continue

When Michael Eisner took over at Disney CEO in 1984, he immediately recognized that the company's animation division was performing poorly. He set in motion plans to turn it around - plans that resulted in classics such as The Little Mermaid, Beauty and the Beast and The Lion King. But in the meantime, he knew that Disney would have to base new rides at its theme parks on original storylines or licensed-in third-party properties. Eisner spearheaded deals with Michael Jackson (for 3-D movie Captain EO) and George Lucas (the creator of Star Wars). Captain EO was an important attraction in itself, with its combination of 3-D and in-theater effects. But Star Tours was a different beast altogether.

Lucas' own Industrial Light & Magic produced the movie footage, which was then carefully synchronized with the motions of the simulators. The total cost ballooneed to a then-astronomical $32 million - but it had been worth it. Simulator rides had existed before, but none had been this convincing. Star Tours proved to be an enduring hit, remaining in place at Disneyland for more than two decades and spawning clones at Walt Disney World, Tokyo Disneyland and Disneyland Paris. Rides such as SeaWorld Orlando's Wild Arctic owe a lot to Disney's creation.

Eventually, in 2010, Disney shuttered the rides at Disneyland, Disney's Hollywood Studios and Tokyo Disneyland. All three underwent a major makeover, re-emerging as Star Tours: The Adventures Continue. Continuing the pioneering spirit of the original creators, the Imagineers this time reworked the ride so that it features multiple storylines, each spliced together from individual scenes. The result? An attraction with more "re-rideability" than most others.

19. Universe of Energy

The original Universe of Energy pavilion at EPCOT Center featured a roof that was covered in 80,000 photovoltaic solar cells. These partially powered the ride vehicles for the attraction within, which transported guests by following guide wires rather than a traditional track. On their way, guests viewed various film sequences about energy production, as well as a diorama featuring audio-animatronic dinosaurs. The chief innovation? This was effectively multiple experiences in one. Guests began by being seated in a theater, which then rotated to face a screen showing a four-minute hand-animated film on the formation of fossil fuels. Then, the entire seating area rotated once again, this time breaking up into six multi-passenger vehicles. After passing through the dinosaur diaroama, they then reassembled into their original theater formation for two more films. Universe of Energy wasn't just special because of the unique ride system. It showed how multiple types of attraction could be combined into one educutional but fun experience - something that was reflected in later "edutainment" attractions such as Earthquake: The Big One at Universal Studios Florida.

In 1996, the attraction was replaced by Ellen's Energy Adventure, an updated version starring Ellen DeGeneres and Bill Nye "The Science Guy".

18. Fantasmic!

Disney has long used fireworks displays and parades to keep guests in its park late into the night. But with the introduction of Fantasmic! at Disneyland in 1992, the company took the concept of evening entertainment at theme parks to a whole new level. Designed to reinvigorate the space in front of the Rivers America, Fantasmic! was a collaboration between Disney's animation studios and its Imagineers. Massive modifications were required to Tom Sawyer Island and the Rivers of America, with equipment being installed underwater to enable the show's range of elaborate effects.

And what effects they are, including towering water screens, pyrotechnics and powerful fountains. Dozens of Disney characters join in the action, both on the water screens and in live-action stunts. Fantasmic! spawned clones at Disney's Hollywood Studios and Tokyo DisneySea, and has continued to be "plussed", with the addition of an enormous, fire-breathing dragon in 2010 being just on example. It has also influenced future Disney spectacles, such as World of Color at Disney California Adventure and Disney Dreamsat Disneyland Paris, as well as shows from rivals such as Universal Studios Florida's Universal 360 - A Cinesphere Spectacular.

17. Walt Disney's Enchanted Tiki Room

In 1963, guests wandering through Adventureland at Disneyland caused enormous traffic jams as they stopped to watch an incredible talking bird. The bird, Juan, was beckoning them inside an all-new attraction: Walt Disney's Enchanted Tiki Room. The attraction was the first to feature the new Audio-Animatronics technology, which had been developed in-house by Disney's Imagineers. Originally designed as a restaurant in which guests would be serenaded by singing birds, it was reworked into a full-blown show featuring a cast of more than 150 talking, singing and dancing birds, flowers, tiki dummers and tiki totem poles.

In may seem quaint by today's standards, but it's difficult to understate the impact of the Enchanted Tiki Room. Almost every theme park dark ride now features some form of animatronics, with Disney's still leading the way. It was a long journey from the tiny birds of the Tiki Room to the 39-feet-tall King Kong animatronics in Kongfrontationat Universal Studios Florida - but one couldn't have happened without the other.

16. Toy Story Midway Mania

Opened at both Disney's Hollywood Studios and Disney California Adventure in 2008 (followed by a third installation at Tokyo DisneySea in 2012), Toy Story Midway Mania has proven to be hugely popular. Too popular, really - the queues for the ride frequently reach more than 3 hours, and FastPass reservations run out early in the day. It's easy to see why. Toy Story Midway Mania pushes the boundaries of theme park technology, using complex computer systems to sychronise on-screen, 3-D action with the actions of guests themselves in their cars. Those guests are equipped with a simple pull-string "gun", which throws various projectiles depending on which of a variety of mini-games they are playing. Perhaps the most significant innovation is the software-based nature of the games. This allows the various games to be swapped out in future, as has already occured on one occasion.