Disney's Imagineers are constantly looking to "plus" the company's theme parks across the globe, adding new rides and attractions. Sometimes, they'll even add an entire new themed land, such as the recently-opened Cars Land at Disney California Adventure.

For every new land that becomes a reality, though, many more never make it past the concept stage. Some progress a little further, with detailed artwork and plans being produced before the plug is pulled for creative or budgetary reasons. All that it left is artwork for fans to gaze at and wonder what might have been.

This is by no means an exhaustive list, but let's take a look at 10 incredible Disney theme park lands that were never built!

10. Sci-Fi City (Tokyo Disneyland)

Disney's Tomorrowlands are difficult to maintain, as they are designed to depict an ever-changing future. At Tokyo Disneyland, the park's owners (the Oriental Land Company) considered replacing the entire area with Sci-Fi City, a "city of the future" that would draw upon diverse influences ranging from Japanese anime to Buck Rogers.

All of Tomorrowland's attractions were in for an upgrade, with Space Mountain, for example, becoming HyperSpace Mountain. Most intriguingly, an all-new attraction dubbed Sci-Fi Zoo would host a variety of audio-animatronic critters form outer space, and guests would be "abducted by aliens" on the UFO Encounter ride. With funds being focused on the construction of Tokyo DisneySea, though, the project didn't go ahead.

9. International Street (Disneyland)

International Street was designed to occupy the space at the north-east corner of Disneyland's Main Street USA, which had been left open for an expansion to connect to the Town Square area. When Disneyland opened, concept art for what was to occupy this space was on show - and it depicted International Street, an area that would celebrate different cultures from around the world.

The street would have hosted a variety of architectural styles, such as an English pub and a Danish Toy Shop. However, it was delayed and ultimately cancelled due to a lack of funds, with Disney instead focusing on finishing off Tomorrowland. The idea, of course, inspired the World Showcase area at Epcot.

8. Big Town USA (Disneyland)

In the 1970s, Disney drew up a long-term masterplan for Disneyland. One of the proposals was to build Big Town USA, a recreation of turn-of-the-century New York City. This would have occupied the site that eventually became home to Mickey's Toontown.

The area would have hosted a variety of shops and restaurants, as well as 3,000-seat theater. Despite Walt Disney's dislike of traditional, unclean amusement parks, it would also have included a Victorian-style funfair complete with a ferris wheel and a roller coaster. The plans were dropped, but the designs for the Paradise Pier area of Disney California Adventure clear drew upon them.

7. Discovery Bay (Disneyland)

Another 1970s proposal for Disneyland was the ambitious Discovery Bay. Designed by legendary Imagineer Tony Baxter, this would have taken over a large section of Frontierland. The area would have been themed around a San Francisco-style harbor, but with fantasy elements such as the Nautilus submarine from 20,000 Leagues Under the Sea and the Hyperion airship from The Island at the Top of the World.

As many as three attractions would be housed in the Nautilus, including a walkthrough, a "undersea" restaurant and a simulator ride. Elsewhere, a roller coaster would wind around a Tesla Coil, and a Chinatown area would host fast food outlets and a shooting gallery. The headliner, though, was a "balloon ascent" attraction themed around The Island at the Top of the World. When that movie bombed at the box office, Discovery Bay was parked.

6. Beastly Kingdom (Disney's Animal Kingdom)

The original design of Disney's Animal Kingdom featured an entire land dedicated to mythical creatures, known as Beastly Kingdom. This would be split into two sub-areas. One of these would be a medieval village, complete with cold stone pubs and thatch-roofed markets, all lit by flaming torches. At its heart would be the Dragon’s Tower, which would host a major dark ride-cum-roller coaster that would be Animal Kingdom’s main thrill ride. As well as featuring an enormous animatronic dragon, this would be Disney’s first inverted roller coaster – with the trains riding underneath the track, instead of on top of it.

The second sub-land would be themed around Greek temples, hosting a dark ride themed around the 1940 animated movie Fantasia. Behind this would be Quest for the Unicorn, an interactive walkthrough hedge maze that challenged guests to find and awaken five golden idols scattered through the maze.

As the costs of building its animal park spiraled, Disney bumped Beastly Kingdom into a “phase 2” expansion of Animal Kingdom. In its place would stand a low cost, hastily thrown-together alternative dubbed Camp Minnie-Mickey, intended to be ripped out when the expansion was given the green light. However, when Disney’s Animal Kingdom finally opened in 1998, it immediately began to cannibalize attendance at Walt Disney World’s other theme parks. Spending money on boosting the performance of those parks became the priority, and when the debut of Islands of Adventure failed to significantly impact on Animal Kingdom’s attendance, Disney CEO Michael Eisner put the plans for Beastly Kingdom on hold indefinitely.