Back in the early 1990s, Disney-MGM Studios was facing criticism from the press and some visitors. The park had debuted in 1989 to huge crowds, but only offered a handful of attractions. This was by design - Disney CEO Michael Eisner had deliberately opted to make it a "half-day park", keeping the cost low but still encouraging Walt Disney World guests to stay for an extra day. By 1991, rival Universal Studios Florida was firing on all cylinders after its disastrous debut a year earlier. Attendance at the park would eventually surpass that at Disney-MGM Studios, and Disney put into place rapid expansion plans. This included the addition of a Muppets-themed area and several smaller attractions. The vast majority of Disney's budget, however, would be spent on a thrill ride to match those over at Universal's park. The result was the Twilight Zone Tower of Terror, an attraction that is still considered by many today to be Disney's best ever. The Imagineers took a simple concept - a drop tower - and turned it into a complex dark ride with some of the most detailed and convincing theming ever seen. 20 years later, first-time guests still sometimes mistake its facade for that of a real hotel. Riders step straight into an episode of The Twilight Zone. After passing through the lobby of the enormous Hollywood Tower Hotel, they are informed via a pre-show video that the hotel was struck by lightning decades ago, sending some of its occupants spiralling into the Twilight Zone. Guests are about to take that same journey, via a very unusual service elevator. There are dozens of little details scattered throughout the Twilight Zone Tower of Terror. Next time you ride, keep your eyes peeled for these 30 hidden secrets!

30. A large-scale building

Take a look at the hotel from the outside, to appreciate its scale. Some 1,500 tons of steel were used to construct it, along with 145,800 cubic feet of concrete. The roof is lined by 27,000 tiles.

29. Inspiration

One of the main inspirations for the exterior appearance of the Hollywood Tower Hotel was The Mission Inn in Riverside, California.

28. A luxurious interior

On the inside, sections of the lobby were inspired by the Millennium Biltmore Hotel in Los Angeles.

27. A real hotel?

From the front of the hotel, you can see a window with a light in it. This is just a dummy room to add to the impression that this is (or was) a real, working hotel. In his autobiography, former Disney CEO Michael Eisner reveals that he suggested that the Hollywood Tower Hotel be an actualhotel, as well as hosting the Tower of Terror. This proved to be impractical.

26. A Moroccan tower

Image: sanctumsolitute, Flickr (license)

The Tower of Terror is a very tall structure, and the back of it is visible when looking at the Morocco Pavilion in Epcot's World Showcase. Decorations have been added to ensure that it blends in when viewed from Hollywood Studios' sister park.

25. Just tall enough

The Hollywood Tower Hotel stands at 199 feet tall. If it were just one foot taller, the Federal Aviation Authority would require it to have a flashing red light on the top.

24. Period hits

Listen out for a host of 1930s-era songs such as We'll Meet Againby Very Lynn drifting out over the garden walls outside the Hollywood Tower Hotel.

23. The opening date

The sign at the attraction's entrance indicates that the Hollywood Tower Hotel opened in 1917. The ride itself opened in 1994.

22. Too many diamonds

On the wall next to the concierge's desk in the lobby, you can see a plaque that awards the Hollywood Tower Hotel 13 diamonds from AAA. In reality, the AAA system tops out at 5 diamonds.

21. The lamp

There are several "Hidden Mickeys" to spot as you navigate the Hollywood Tower of Hotel. The lamp in the concierge desk is an antique, but has a familiar 3-circle pattern on it.