One of the most famous couples in Hollywood joined one of cinema’s legendary directors for a film that everyone was talking about before it even hit theaters. Stanley Kubrick’s Eyes Wide Shut celebrated its 15th anniversary this week. The film stars Tom Cruise as a restless doctor, Bill Harford, whose curiosity takes him on a nightlong sexual odyssey that threatens his life and marriage. Nicole Kidman — who was Cruise’s real-life spouse at the time — plays his wife, Alice, whose sexual fantasies and equally wandering eye rattle her husband’s deepest insecurities. Sex, marriage, and mystifying symbolism: a combination only Kubrick could make as compelling as he did. Here are 25 facts, details, and asides about Eyes Wide Shut you might have missed.

Kubrick was extremely happy with the way Eyes Wide Shut turned out and considered it his greatest film.

According to Kubrick’s daughter Katharina, the director had plans to adapt the movie from Arthur Schnitzler’s 1926 novella Dream Story for over 30 years:

He obviously thought that it was a subject matter close to anyone who’s ever been in a relationship of whatever persuasion. I don’t know what his intentions were, I know that he wanted to do it for over 30 years, and that when he first found the story he decided along with my mother that they weren’t old enough or wise enough to deal with such a powerful subject matter.

Kubrick has a cameo in the film. He’s sitting across from Bill’s table at the Sonata Café.

Tom Cruise and Nicole Kidman’s love scene was shot on a closed set. “Stanley had to coax me into some of the sexuality in the film in the beginning, but we shot things that were a lot more extreme that didn’t end up in the movie,” Kidman told press in 2012. “I did feel safe — I never felt it was exploitive or unintelligent.” Cruise emphasized Kubrick’s focus of the film to Roger Ebert in 1999: “Sex itself wasn’t what interested Stanley. The movie’s about many things but especially the dynamic of a relationship that’s affected by the raw emotions of obsession and jealousy. About how one little event in your life can take you off into such debilitating emotions.”

The Guinness World Records recognized Eyes Wide Shut as the longest continual film shoot — over 15 months. Cruise and Kidman’s contract was open-ended. This meant they couldn’t be released from the project until Kubrick gave his word, however long the shoot lasted.

The room in the morgue Bill visits to see Mandy’s body is located in wing C, room 114 (C-Rm114, or CRM-114). CRM-114 was the name of the radio equipment in Kubrick’s film Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb and the serum given to Alex in A Clockwork Orange.

Harvey Keitel and Jennifer Jason Leigh were set to play Victor Ziegler and Marion Nathanson. They shot several scenes, but both stars had scheduling conflicts and left the film. Sydney Pollack and Marie Richardson took over the roles. Other stars reportedly up for Victor: Woody Allen (Kubrick was a fan). And, brace yourself, Steve Martin was being considered for the part of Bill.

Cruise hated his character: “‘I didn’t like playing Dr. Bill. I didn’t like him. It was unpleasant,’ admitted Cruise a year later in the only public criticism he’s ever given. ‘But I would have absolutely kicked myself if I hadn’t done this.'”

The Harfords’ New York City apartment resembled the one Kubrick and his wife, Christiane, lived in during the 1960s. Tom Cruise stated: “The apartment in the movie was the New York apartment he and his wife Christiane lived in. He recreated it. The furniture in the house was furniture from their own home. Of course the paintings were Christiane’s paintings. It was as personal a story as he’s ever done.”

Cruise and Kidman lived like their characters when the cameras weren’t rolling. “The couple slept in their characters’ bedroom, chose the colors of the curtains, strewed their clothes on the floor, and even left pocket change on the bedside table just as Cruise did at home,” writer Amy Nicholson revealed. Kubrick even discussed the couple’s real-life marital anxieties in private conversations so the actors could tap into their emotions while filming.

Kidman participated in a shoot without Cruise, which captured sex scenes (50 different positions) with a male model (used in the naval officer dream sequences). To add to Cruise’s anxiety, Kubrick forbade Kidman to discuss the shoot.

Cinematographer Larry Smith tested different film stocks before choosing a discontinued Kodak brand. Most of the film is shot with ambient lighting (Christmas tree lights, regular table lamps, etc.).

Bill’s mask is modeled from the face of Ryan O’Neal, referencing Kubrick’s Barry Lyndon.

There is a reference to Kubrick’s first feature, Fear and Desire, visible on a television set. The 1973 film Blume in Love is playing, about a divorce lawyer whose own marriage is breaking up (sound familiar?). The movie is directed by Paul Mazursky, who starred in Fear and Desire.

Kubrick shot the film in England (where he lived), instead of New York City, due to his fear of flying.

Always the consummate perfectionist, Kubrick once made Cruise do 95 takes walking through a door. The demands did take their toll (Cruise developed an ulcer), even though the cast has no regrets.

Filmmaker Filippo Biagianti created a documentary about the Venetian Carnival masks used in the film, which features an interview with the artist, Franco Cecamore.

The 19-century English estate Mentmore Towers in Buckinghamshire was used as the site of the masked orgy.

The Mentmore mansion was built for the esteemed Rothschild family, who hosted surreal masked parties that saw guests like Salvador Dalí in attendance.

The Star of Venus can be seen throughout the film. It’s sometimes known as the Star of Ishtar — the Babylonian goddess of fertility, love, war, and sex.

The story is set during Christmas, and a Christmas tree can be seen in most scenes. However, the masked orgy is the only setting without a tree, depicting it in stark contrast to the “real” world.

The masked orgy features music from composer Jocelyn Pook, who created a track called “Backwards Priests,” later retitled to “Masked Ball.” It contains samples of a Romanian Orthodox Divine Liturgy played backwards.

Kubrick’s daughter Katharina and his grandson Alex Hobbs appear as the mother and the child patient examined by Bill.

The film’s co-writer Frederic Raphael stated that the proposed titles of the film included You and Me and The Female Subject. Kubrick personally chose Eyes Wide Shut.

The identity of the “Red Cloak” figure (played by Leon Vitali) is never revealed, but the actor’s real name is cited in the newspaper article about Mandy/Amanda’s death, stating: “After being hired for a series of magazine ads for London fashion designer Leon Vitali, rumors began circulating of an affair between the two. Soon after her hiring, Vitali empire insiders were reporting that their boss adored Curran — not for how she wore his stunning clothes in public, but for how she wowed him by taking them off in private, seductive solo performances.