The castle will house what is expected to be the Wizarding World's signature attraction. Several people familiar with the project, including one person directly involved, said the ride will be what's known as a "robocoaster" — a ride system in which guests sit in seats suspended from a robotic arm that can swivel and swoop in multiple directions while it advances along a track.

Plans show the track snaking through more than a dozen scenes, though what those scenes will be remains a mystery. The attraction, according to the people familiar with it, will also feature an elaborate pre-show queue with special effects such as floating candles and snow falling indoors.

Part of the Wizarding World is being built in the Lost Continent section of Islands of Adventure, and documents indicate that two existing attractions there — Dueling Dragons, where riders choose between two intertwined roller coasters, and the Flying Unicorn, a children's coaster closed last year as part of the Potter construction — will be incorporated into Harry Potter's world.

Both rides are expected to be re-themed with Potter story lines. Records show, for instance, that Universal plans to add a large tent at the entrance of Dueling Dragons, which fans have speculated will ultimately be converted into a re-creation of a wizarding tournament from one of the books in which one of the events involves stealing eggs from dragons.

Whatever is ultimately included when the Wizarding World opens next year, newer additions will soon follow. Universal's licensing contract with Warner Bros. requires the resort to add elements from the final movies in the series — the last of which isn't scheduled to arrive in theaters until 2011.

The contract even states that the later movies must be represented "in generally similar per-movie proportion" as the first five films.