Theater owners have bemoaned declining audience numbers for years. So it might be a surprise to learn of one exhibitor that packs them in despite showing old movies and charging upward of $85 a ticket.

Secret Cinema has been putting on films in London since 2007. The latest, 1987’s “Dirty Dancing,” wrapped July 24 after six days of sold-out screenings that raked in $2.5 million. The company offers an “immersive,” interactive experience, with sophisticated sets, actors, and staged events. Audience members are encouraged to wear costumes.

For “Dirty Dancing,” 30,000 attendees descended on an East London park that had been converted into a fictional Catskills resort. Decked out in ’60s attire, they indulged in outdoor games and laughed at cheesy stage acts for hours before the film finally lit up the huge outdoor screen.

Some of Secret Cinema’s previous productions have been even more ambitious. Its 2014 “Back to the Future” extravaganza re-created a ’50s-era American town. Last year, “The Empire Strikes Back” wowed the crowds who sipped drinks in a version of the famous “Star Wars” cantina, and watched Storm Troopers, rebels, and assorted aliens mill about.

“They want to meet people; they want to become part of the movie,” says Fabien Riggall, Secret Cinema’s creator. “It’s about a six-hour experience of which only one-and-a-half hours is a screening — the rest of it is interactive theater.”

It all adds up to healthy numbers. “The Empire Strikes Back” brought in $8.4 million and more than 100,000 moviegoers over 100 days. This past spring, zombie pic “28 Days Later,” shown in a disused printing plant dressed up as a hospital, made $1.7 million. Both movies ranked in the top 10 at the British box office during part of their runs.

Ticket prices have prompted grumbling. At “Dirty Dancing,” college lecturer Sue Dixon estimated that she paid more than $150 for the ticket, her dress, food, and other gear. Still, “it’s the experience,” says Dixon, 46, adding that she avoids movie theaters because they’re “too noisy.”

Riggall hopes to export Secret Cinema to the U.S. He screened 1966’s “Blow-Up” in 2010 inside an old photography studio in Brooklyn and has been scouting locations in various cities, including Los Angeles.