Shock announcement as Prince Harry and Meghan Markle to appear in new ABC News show

Prince Harry and Meghan Markle are going to feature in a new special programme about Disneyland's 70th anniversary. This weekend, the US's ABC News will release an in-depth feature about the history of the park, which will also include some Hollywood big names who will reveal their fondest memories of it.

The Happiest Story on Earth: 70 Years of Disneyland - A Special Edition of 20/20 wil air this Sunday, September 21. According to People magazine, ABC News wrote in a statement: "Viewers will hear reflections on childhood visits to the park from some of Disney's biggest fans including Hollywood's Neil Patrick Harris, Jamie Lee Curtis, Jon Favreau, Patrick Warburton and Tiffany Haddish.

"And an exclusive message from Prince Harry and Meghan, Duchess of Sussex, on what the park means to them and their family.

The Duke and Duchess of Sussex visited the famous theme park earlier this summer and their visit coincided with Princess Lilibet's fourth birthday on June 4.

Harry can be heard saying in the trailer: "Prepare yourself, you're about to be blown away."

Meghan chimed in: "We were just so lucky."

The pair was likely referring to June's two-day visit.

At the time, Meghan took to her Instagram account to post a video with clips and pictures of the whole family enjoying their trip, with the message: "Thank you @disneyland for giving our family two days of pure joy!"

In another short clip in the trailer, Harry reveals that his favourite Disney attraction is Space Mountain, which he tried with his wife while there in June.

Space Mountain is a space-themed rollercoaster inside the park.

Meghan added after her husband's revelation: "Still one of your favourite rides by the way."

According to People, Other Hollywood stars who will appear in the special include Julie Andrews, who visited the park with Walt Disney himself, actor Josh Gad, Star Wars creator George Lucas, Lin-Manuel Miranda, Stephanie Beatriz, and John Stamos.

Viewers will get a rare behind-the-scenes look at how the beloved park, which celebrates its 70th year this summer, operates.

They will also see some of the things and new attractions expected to come in the future.

The Happiest Story on Earth: 70 Years of Disneyland - A Special Edition of 20/20 will premiere on Sunday, September 21, at 8pm ET (Tuesday, September 22, at 1am UK time) and will be available the next day on Disney+ and Hulu.