The Mouse House kicked off a massive U.S. train tour promoting its upcoming film “A Christmas Carol” by holding a press conference Thursday with Jim Carrey and director Robert Zemeckis at Union Station in L.A.

The event allowed guests to tour the train’s interactive exhibits and watch 3-D clips from the film, all while munching on sugar cookies and listening to Christmas carols.

“It’s kind of like Hollywood on wheels, going out into the world,” Carrey said of the tour’s 16,000-mile route visiting 40 cities in 36 states.

As one of the biggest publicity stunts in recent memory — and free to boot — Disney has gutted four passenger cars and converted them into an elaborate display of memorabilia and technology from the film.

The studio will open the traveling exhibit to the public for a short stint at each stop.

“When the circus would come to town 100 years ago … everyone would turn out for the train,” Zemeckis said. “That is what I think is really amazing, being able to have a conveyance that can take this most high-tech, virtual storytelling and put it in an exhibit so people can actually experience it.”

Other than the train, Zemeckis said his favorite part of the tour is the inflatable theater that will be hauled to each location so attendees can watch footage from “A Christmas Carol” in 3-D.

“That to me is really the cornerstone of this whole thing,” he added.

The train will be at Union Station and accessible to the public from today through Monday before beginning its tour.

Information on the train and its schedule can be found at Disney.com/christmascaroltraintour.