When the 5th Dimension doors open, the first lights that come on simulate looking down a lift shaft; the idea was to disorientate guests into thinking they were lying face down at the top of a lift shaft.

As for the drops, the opening is at a height of 157 feet up (but it only drops 130, or 13 stories down from there). The first smaller drop in darkness is about 8 stories, then back to the top for the 13 story plunge doubled. In case you were also wondering, the speed of the drop is about 39 MPH, and the drop itself only lasts for around 2 ½ seconds, though it seems a lot longer!

Since its opening, not much has changed. The post ride video (at the base of the drop shafts) has been changed, new projection systems were fitted to the corridor floors, the audio has been upgraded, seatbelts introduced, the 5th Dimension eyeball no longer shows your ride vehicle, just a generic one, and of course the 2,3 and 4th drop profiles were introduced:

The Twilight Zone Tower of Terror™ (second show enhancement- double drop) May, 1996.

The Twilight Zone Tower of Terror™: Fear Every Drop! (third show enhancement) March 1, 1999.

The Twilight Zone Tower of Terror (fourth show enhancement - new drop sequence places the computers in control of the ride experience, making each ride sequence random) December 31, 2002.