The multi-million dollar expansion of the Wizarding World of Harry Potter doubles the size of the tourist attraction, which originally opened in 2010. It will officially open to the public on Tuesday, July 8.
Visitors can now experience the world of the popular book and movie series in more painstaking detail than ever before, thanks to the impressive rendering of magical locations including Diagon Alley, Gringotts Bank and the Leaky Cauldron pub.
A new Hogwarts Express attraction allows fans with passes to both parks to ride the iconic locomotive from the new Universal Studios attraction to the existing Hogsmeade Village in Universal's Islands of Adventure.
Technology including digital video screens in place of windows makes the journey highly immersive.
Deep within Diagon Alley itself, the new ride Escape from Gringotts plunges visitors into a dramatically realistic world that combines talking holograms, actors and robotic characters with a fast-paced, 3D rollercoaster experience that sees Harry Potter himself appear on a dragon.
Talking to journalists on the red carpet at the launch event, Bonham Carter, who filmed new scenes as villain Bellatrix Lestrange, said, "It was fun, although first of all I was worried if I could get into the costume.
"It took them two years to make the ride, it's very sophisticated, full of cutting-edge stuff and very, very complicated."
Tom Felton, who played Draco Malfoy in the movie series, admitted to Digital Spy that the tourist experience will surpass that of the actors' on-set filming, thanks to the all-encompassing attention to detail.
Stars Daniel Radcliffe, Emma Watson and Rupert Grint did not attend the launch. Also absent was author JK Rowling whose new book The Silkworm, written under the Robert Galbraith alias, is released today (Thursday, June 19).
The Wizarding World of Harry Potter expands with Diagon Alley experience - photo gallery: