Disney is renowned for investing huge sums in the creation of new rides and shows for its theme parks. Crucially, it doesn't just allocate significant amounts of money to build the actual ride systems for its attractions. Unlike most other theme park operators, it also spends vast amounts on scenery, props and other theming elements.

Ride designer John Wardley, who created classic attractions such as Nemesis at Alton Towers, recently remarked that the theming budget for the UK park's £18 million The Smiler roller coaster "wouldn't have covered the decoration of one of Disney's post-ride shops". Given that Alton Towers is owned by the second largest attraction operator in the world behind Disney, the Merlin Entertainments Group, this shows the enormous level of investment that Disney makes.

We thought it would be fun to analyse which are the most expensive Disney rides ever built, and why they cost so much to create. That's extremely difficult, because Disney does not generally release official cost figures for its rides (and even if they did, theme park operators are notorious for artificially inflating such figures). But we at least have an idea of which of the company's rides consumed the most dollars.

Let's take look at 10 of the most expensive Disney rides ever built...

Note: All of the cost figures given below are estimates (we've linked to our sources), and should all be taken with an appropriately large pinch of salt. They also do not take account of inflation.

10. Mission: Space (Epcot)

Estimated cost: $100 million (source)

What is it? Riders go through astronaut training for the first manned mission to Mars aboard the X-2 Deep Space Shuttle. They are given one of four roles (navigator, pilot, commander or engineer), before being exposed to the full force of a rocket launch into deep space.

Why was it so expensive? This is one example of an attraction where the ride system probably ate up the lion's share of the cost. Mission: Space is made up of four separate centrifuges, each containing 10 capsules that hold four riders each. When you "take off", the capsules are tilted and spun at high speeds. This exposes you to forces of more than 2.5G (effectively multiplying your weight by 2.5 times), and pushing you back into your seat.

9. Expedition Everest (Disney's Animal Kingdom)

Estimated cost: $100 million (source)

What is it? Opened as Animal Kingdom's first major coaster and first ride to feature a mythical animal, Expedition Everest is a forwards / backwards mine train coaster in which guests encounter the legendary Yeti through special effects and an animatronic figure.

What was it so expensive? In addition to the coaster itself, there were several other elements that contributed to the enormous cost of Expedition Everest. The Forbidden Mountain that hosts the ride was created using 5,000 tons of structural steel and 10,000 tons of concrete. A rigid steel structure holds the mountain in place. More than 2,000 gallons of stain and paint were used on the mountain's rockwork and the buildings in the surrounding village.

To recreate the lowlands surrounding Mount Everest, more than 900 bamboo plants, 10 species of trees and 110 species of shrubs were planted. And the ride's queue features hundreds of authentic items, with climbing gear being taken from the base of Mount Everest and computers and ladders being purchased from Nepalese stores.

One expensive element of Expedition Everest no longer works properly. The animatronic yeti was the most ambitious audio-animatronic figure ever built by Disney's Imagineers. It stands at 22 feet tall, and originally featured movement controlled by 10 actuators. It was able to move five feet horizontally and two feet vertically in its original guise.

A few months after the ride opened, the concrete foundation on which the Yeti stands cracked, and his full range of movements was put to an end. Instead, a disco-style strobe light now flashes behind him to give the impression that he is moving.

8. Pooh's Hunny Hunt (Tokyo Disneyland)

Estimated cost: $130 million (source)

What is it? Pooh's Hunny Hunt is a groundbreaking "trackless" dark ride at Tokyo Disneyland, and not to be confused with the more basic Winnie the Pooh-themed attractions at other Disney parks.

Why was it so expensive? The ride dispenses with the traditional OmniMover system used by rides such as the Haunted Mansion. Instead, it uses a unique local positioning system (LPS), enabling computers to control the movement of each individual car. The cars can appear to have a mind of their own as they zip in and out of various iconic scenes from Pooh stories. As the wheels are hidden, they seem to glide seamlessly from one area to another, and the system was so successful that it was reused for the Aquatopia ride at neighbouring Tokyo DisneySea.

7. Ratatouille: L'Aventure Totalement Toquée de Rémy (Walt Disney Studios, Paris)

Estimated cost: $120 - $150 million (source)

What is it? Walt Disney Studios' Ratatouille dark ride, based on the 2007 Pixar film of the same name, will see guests "shrunk" down to the size of a rat. The ride will begin in Gusteau's restaurant, before taking riders on a wild chase through key scenes from the movie. Disney will reuse the trackless ride system from Tokyo Disneyland's Pooh's Hunny Hunt attraction, which allows full 360 degree rotation of the ride cars.

Why was it so expensive? Disney's Imagineers claim to have invented a completely new ride system for the Ratatouille attraction, suggesting that it may not be a straight-up reuse of the Pooh's Hunny Hunt trackless system. The theming budget is also huge - the surrounding area will be themed around a Parisian courtyard, and there'll be plenty of oversized props and scenery elements in the ride itself to convince riders that they are rat-sized.

6. Twilight Zone Tower of Terror (Disney's Hollywood Studios) - $150 million

Estimated cost: $150 million (source)

What is it? A twist on traditional drop tower rides, the Tower of Terror is located inside a full-scale mock hotel dubbed the Hollywood Tower. After an introduction from Twilight Zone host Rod Serling, guests enter an elevator that drops them multiple times at speeds faster than free-fall.

Why was it so expensive? The Twilight Zone Tower of Terror was built at the height of the rivalry between Disney-MGM Studios and Universal Studios Florida, and for once Disney was happy to crow about its price tag. It features one of the most elaborate ride buildings ever constructed. Some 1,500 tons of steel were used to construct the Hollywood Tower Hotel, along with 145,800 cubic feet of concrete. The roof is lined by 27,000 tiles.

The unique ride system combines multiple elements. Guests sit in Autonomous Guided Vehicles (AGVs), which rise up to the corridor scene in a Vertical Vehicle Conveyance (VVC). When they reach the Fifth Dimension corridor, the AGVs come into their own. Rather than riding on a track, the AGVs are guided by wires under the floor. When they reach the far end of the corridor, they lock into another vertical motion cab, which handles the actual drop sequence. This is powered by two enormous motors, which are 12 feet tall, 35 feet long and weigh a massive 132,000 pounds.