10. The Excavator (Disney's Animal Kingdom)

The original plan for the DinoLand U.S.A. area of Disney's Animal Kingdom included a major thrill ride themed around a former sand and gravel pit. The site would feature an enormous piece of leftover machinery: The Excavator. This ore car circuit was to form the basis for a huge, heavily-themed, mine cart-style roller coaster that would be one of Disney's Animal Kingdom's headline thrill rides. The storyline would be that paleontology students had once again restarted the Excavator, using it to transport dinosaur fossils.

The Excavator was dropped from Animal Kingdom's opening day line-up due to the spiralling costs of building the park's zoo attractions. It was felt that Dinosaur (then known as Countdown to Extinction) would be sufficient as a thrill ride to anchor the DinoLand U.S.A. area, and the plans were parked. The space allocated for the Excavator was eventually occupied by TriceraTop Spin and Primeval Whirl.

9. Time Racers (Epcot)

In the early 2000s, Disney planned to completely overhaul Epcot's Future World area. At the heart of that plan sat Time Racers, a futuristic roller coaster set inside Spaceship Earth. The Future World project was dubbed Project Gemini, and was focused on thrill rides. The entire area was to be renamed Discoveryland (the same name used by a land at Disneyland Paris), and many attractions would have been updated or removed altogether. Time Racers would have taken over Spaceship Earth, the iconic structure that sits at the entrance to Future World. The existing, slow-paced Omnimover dark ride that occupied the interior of the building would have been ripped out. In its place would have been a steel roller coaster reminiscent of Space Mountain: Mission 2 at Disneyland Paris.

Little is known about the proposed attraction, other than that it would have seen riders racing past scenes from different periods in time. It would, then, have retained the essence of Spaceship Earth, but would have been aimed squarely at thrill-seekers rather than families. A projection system would have been employed to take riders back into recognisable scenes from history, then off into the future. Project Gemini proved to be too expensive for Disney to pursue, with a rumored price tag of around $500 million. Had it gone ahead, Epcot could be a very different park today. Instead, Siemens took over sponsorship of Spaceship Earth, and the existing ride was given a makeover - ensuring that it will continue to whisk riders through history for some time to come.

8. Animal Carousel (Disney's Animal Kingdom)

Disney's theme parks always have an iconic structure at their center, and at Animal Kingdom that role is fulfilled by the enormous Tree of Life. It also hosts an attraction, It's Tough to Be a Bug, which is themed around Pixar's It's a Bug's Life. During the planning phase before the park was built, however, a more traditional ride was considered as the centerpiece of the park: a carousel. The Animal Carousel would not have been a mere fairground-style midway ride, however. Instead, it would have offered three different experiences, in one unique attraction.

The first experience would have been a Dumbo the Flying Elephant-style flying ride, featuring insects and birds instead of elephants. Riders would have been equipped with a joystick, enabling them to control the height of their gondola. The second experience would have been a more traditional carousel, featuring a variety of animal species from all over the world. The final experience was also a carousel, but in this case set on water. The boat-style cars would have been themed around marine creatures, and would have sat in a moat that would have surrounded the Animal Carousel. In the end, the Tree of Life was selected over the Animal Carousel as the icon of Disney's Animal Kingdom. It probably offers a more instantly-recognisable, simple-to-communicate image of the park, but the 3D show within is perhaps a less innovative attraction than the Animal Carousel would have been. But we'll never know...

7. Rhine River Cruise (Epcot)

The early plans for EPCOT Center included a boat ride in the Germany Pavilion. This would have seen guests boarding a "cruise boat" for a trip down the Rhine and other rivers, providing a visual overview of Germany's heritage. Miniature recreations of the Black Forest, the Ruhr Valley and Heidelberg would have been on show. Disney went as far as building part of the show building for the Rhine River Cruise, but the ride was not completed. Like many attractions planned for the World Showcase, the likely reason is that Disney could not secure a corporate sponsor to fund the construction costs.

6. Dick Tracy's Crimestoppers (Disney's Hollywood Studios)

Disney has produced several interactive rides, most of them based on the Toy Story franchise. The likes of Buzz Lightyear's Space Ranger Spin and Toy Story Midway Mania see guests blasting away at relatively innocent targets such as Zurg's toy minions, balloons and smashable plates.

The laser gun technology employed by the Buzz Lightyear ride could have been put to a very different use had a plan to base an attraction on Warren Beatty's 1990 movie Dick Tracy gone ahead. This would have seen guests shooting at audio-animatronic HUMAN adversaries, as they raced through the streets of Chicago blasting bad-guys. In the end, Dick Tracy was not quite the success that Disney had anticipated. Plans to install the ride at Disney-MGM Studios and Disneyland were dropped, along with plans to bring a version of the ride to Disney-MGM Studios Europe, a second park that was originally planned for the EuroDisney resort.