Her Grandfather Drew Mickey. Her Father Built the Camera. Now Leslie Iwerks Is Filming What Comes Next.

Stand in the village square in World of Frozen just after the light goes blue and something faintly ridiculous happens. You know the mountain behind the rooftops is steel and shotcrete. You know the snow along the eaves has never once been cold. And you catch yourself lowering your voice anyway, because it feels like somewhere people live.

Pulling that off is a job. Somebody chose the pitch of those roofs, the temperature of the light in those windows, the exact moment the fountain catches you. On August 20, a documentary lands on Disney+ that finally hands those people a microphone and lets them explain how they do it.

Disney Worldbuilders premieres August 20, four days after its world premiere at D23: The Ultimate Disney Fan Event on Sunday, August 16. It is directed by Leslie Iwerks and produced by her company, Iwerks and Co., for Disney+. The interview list is the part that made the fan sites sit up: Bob Iger, Josh D’Amaro, James Cameron, Jon Favreau, Kevin Feige, Jennifer Lee, Pete Docter, Dave Filoni and Jared Bush, all circling one question. How does a story stop being a movie and become a place you can walk through?

The name on the director’s card is half the story

Leslie Iwerks did not wander into this subject. She is the third generation of her family to spend a working life inside it, and the first two generations are the reason any of this exists.

Her grandfather, Ub Iwerks, was Walt Disney’s first partner. The two of them met as young commercial artists in Kansas City. When Walt lost the rights to Oswald the Lucky Rabbit in 1928 and needed a new character fast, Ub helped design the mouse and then animated the first Mickey cartoon, Plane Crazy, essentially on his own. Disney’s own archives put his output at something like seven hundred drawings a day. He later won two Academy Awards for scientific and technical achievement, one in 1959 for an improved optical printer and one in 1964 for perfecting color traveling matte photography, and he was named a Disney Legend in 1989, eighteen years after his death.

Her father, Don Iwerks, followed him onto the lot in 1950 as a laboratory technician. He was drafted into the Korean War almost immediately, served two years in the Signal Photo Corps, came home and went straight back to Disney. In January 1953 he moved to the Studio Machine Shop, was offered a camera technician job, and started work on 20,000 Leagues Under the Sea.

The machine that put you inside the picture

Here is where the family story and the documentary’s subject become the same story.

Don helped develop the 360-degree Circle-Vision camera: a ring of lenses shooting in every direction at once, so the footage could be thrown back onto a full circle of screens with the audience standing in the middle of it. It opened with Disneyland in 1955, inside an attraction called Circarama, U.S.A. The first film, A Tour of the West, was projected from eleven 16mm projectors. Later versions used nine.

Read that again with Pandora in mind. In 1955, a man in a machine shop in Burbank built a rig whose entire purpose was to stop you watching a picture and start putting you inside one. Sixty-two years later Disney opened a valley of floating mountains in Florida that does the same thing with rockwork and fiber optics. The tools changed completely. The ambition did not move an inch.

The rest of Don’s career reads like a tour of the things people remember. America the Beautiful, the best loved of the Circle-Vision films, ran at Disneyland for more than seventeen years and later played at Magic Kingdom, EPCOT, Tokyo Disneyland and Disneyland Paris. He taught an Italian crew to run the camera for the 1961 exposition in Turin. He built film equipment for the 1964 New York World’s Fair, engineered the 3-D and in-theater effects for Captain EO, and built the projection system for Star Tours. Working alongside his father, he helped refine the sodium vapor process and built the cameras and optical printers behind the “Jolly Holiday” sequence in Mary Poppins.

Asked once to name the high point, he did not pick a movie. “In my career, EPCOT was most outstanding,” he said, and then talked about theaters. Two nine-screen Circle-Vision houses, the five-screen wraparound in the France pavilion, the rear-projection stage behind The American Adventure. Three decades in and the man was still thinking about how to surround somebody.

The Academy gave him its Gordon E. Sawyer Award in 1997 for a lifetime of technical contribution. Disney made him a Legend in 2009, at the very first D23 Expo. And on the evening of July 9 this year, at 96, Don Iwerks died.

“Don embodied that rare combination of heart, ingenuity, and passion that has always defined Disney,” Josh D’Amaro said at the time. He closed by sending condolences to a family “whose enduring connection to Disney has helped shape its legacy for over a century.”

Six weeks later his daughter’s film about worldbuilding premieres at the same event that made him a Legend. Nobody planned that. It is still the most Disney thing about the whole enterprise.

Nine years, seven lands, three continents

The film arrives in the middle of the busiest stretch of park building the company has ever attempted, and it helps to see the recent run laid out end to end.

One naming note, because this fandom will absolutely catch it: Tokyo DisneySea’s Frozen area is officially Frozen Kingdom, one of three ports inside Fantasy Springs. Hong Kong and Paris have World of Frozen. They are different lands with different layouts, and the words are not interchangeable.

Who is in the room

Disney published the participants with their current titles, and the titles are worth reading closely, because they capture a company mid-handover.

Bob Iger appears as former chief executive and senior advisor, and as an incoming Disney Legend; he is in the 2026 class being honored at this very D23, and he remains on the board until he retires on December 31. Josh D’Amaro appears as chief executive, a job he took on March 18 after running Disney Experiences, which means the man now leading the company came up through the parks. Those two bracket everyone else.

Then the builders. James Cameron, a Disney Legend himself, on turning Pandora into somewhere with humidity. Jon Favreau, also a Legend, and Dave Filoni, president and chief creative officer of Lucasfilm, on Star Wars becoming a place with a street plan. Kevin Feige, president of Marvel Studios, on Avengers Campus. Jennifer Lee, who wrote Frozen and co-directed it, and Jared Bush, now chief creative officer of Walt Disney Animation Studios, on Arendelle and Zootopia standing up as real streets. Pete Docter, chief creative officer of Pixar, rounds it out.

The line that explains the film

Iwerks has said that what she was really chasing was an origin, and that she kept finding the same one.

“I wanted to understand what ignites the imaginations of the storytellers behind some of the world’s most beloved stories,” she said. “As I sat down with each of them, I discovered a common thread: they often traced their creative journeys back to a single childhood moment, walking through the gates of Disneyland and realizing that impossible dreams could become real.” Her hope, she added, is that audiences leave “with that same sense of possibility and inspiration.”

That is a lovely thing for a Disney documentary to say about Disney, and it is also a claim being made by the company about itself. Take it as an authored account rather than an audit. The value here is access, not scrutiny: nine people who have actually done this work, on the record, at the same moment, describing how they think it is done. That is rarer than it sounds, and it will still be useful in thirty years.

The next few years, as far as anyone will say

Disney says the film includes looks at lands still being built. Here is the state of play going in, so you can measure the footage against the record.

Five of those six have no opening year, and that is not us failing to look it up. Disney has not said. Announcing a land and announcing a date are two separate events at this company, sometimes years apart, and the space between them is where a lot of fan speculation gets born and then passed around as fact. So we are drawing the line exactly where Disney drew it. When a date is announced, we add it to that table and note the change. D23 runs August 14 to 16, and the Experiences showcase is precisely where opening years tend to land, so this page may look different by the following Monday.

The gap between “announced” and “dated” is the real story of this moment. Tropical Americas has a year. Nothing else at Walt Disney World does. Abu Dhabi is real and moving, with an unusual structure: Miral funds, builds and will operate the resort while Walt Disney Imagineering leads the creative design, which is why Disney can commit to a seventh resort without carrying the construction cost. D’Amaro has publicly framed a project that size as a year or two of design plus four to six years of building. Do that arithmetic gently.

Why the sixteenth of August matters

D23 runs August 14 to 16 at the Anaheim Convention Center, and it has become the place where opening years get handed out. Premiering a film about the philosophy behind the announcements in the same week as the announcements is not an accident, and it is a good trick: you leave the hall with the news and the reasoning at the same time. Four days later the same film reaches everyone with a Disney+ login.

It is also the first D23 with D’Amaro in the chief executive’s chair and Iger in the audience as an honoree. If you want to know what story the company is telling about itself right now, watch those two on the same screen.

What we will be watching for

Three things. How much real construction footage survives the edit, and how carefully it is framed. Whether the conversations allow any daylight for difficulty, the compromises and the ideas that did not work, or stay in the warm. And whether the film says anything about scale, because worldbuilding at Disney is also an operations problem: the company’s own figures put 80,000 cast members at Walt Disney World, which it describes as the largest single-site employer in the United States.

There is a competitive edge to the timing too. Universal opened Epic Universe in Orlando on May 22, 2025, a whole new gate built on the same premise that people will travel for a world rather than a ride. Disney no longer has this idea to itself, and a film arguing that story-first worldbuilding is a discipline rather than a purchase order is an argument worth making out loud.

The part that will stay with you

Iwerks has a real track record of standing back and letting people talk. The Imagineering Story, six hours of it, went up on Disney+ the day the service launched in 2019. Disneyland Handcrafted arrived this January, built out of archive footage from the year before the park opened. She is not a filmmaker who rushes anyone.

And running underneath the whole thing is a fact nobody at Disney had to script. A man helped draw a mouse. His son built the machine that wrapped a picture all the way around you. His granddaughter now points a camera at the people doing the same job with lidar and rockwork and fiber optics, and asks them where it started. Every one of them says: a day at Disneyland, when I was small.

The tools keep changing. The moment on the other end of them has not changed since 1955. That is what this documentary is actually about, and it is a fine reason to give it two hours on the twentieth.

Also in our Disney coverage: The Magic of Disney Animation opens September 14, and Descendants: Wicked Wonderland tops Disney+ worldwide.