The workshops at companies owned by LVMH Moët Hennessy Louis Vuitton are usually secretive places. But for only the second time in its history, the French conglomerate, which owns 60 of the world's most famous luxury brands, opened to the public to more than 40 sites in six European countries, including Dior’s couture salons, Vuitton’s leather goods facility, Bulgari's jewelry-making shop, and the vast champagne cellars of Moët & Chandon.

They call it Les Journées Particulières, or, in English, "Special Days."

I happened to be in the City of Light during this special weekend and headed directly to 38 Avenue Montaigne, the headquarters of Christian Dior. It's no wonder that lines snaked around the buildings housing various Dior stores as well as the salons where haute couture creations are made and sold to select customers. (Guests made advance reservations for the tour, but most walk-ups could gain admittance after a wait of up to three hours.)

It was here that Dior founded the fashion house that bears his name in 1946 and showed his first collection the next year. Labeled the "New Look," it transformed the fashion world.

The spirit of the fabled couturier permeates the 18th-century mansion, with its black-and-gray-tiled floor and winding staircase lined with black-and-white photos of such notables as Marlene Dietrich, Rita Hayworth and Aly Khan, Humphrey Bogart and Lauren Bacall, and fashion editor Carmen Snow. The latter coined the phrase upon seeing Dior's first collection that emphasized a cinched waist, ample bustline and enhanced hips: "My dear Christian, what a new look."

An embroidered strapless dress that Nicole Kidman recently wore to the Cannes Film Festival is displayed in an alcove. The princess gown that Jennifer Lawrence wore (and tripped in) when she won this year's Oscar for Best Actress is featured on another staircase, along with other Dior creations.

"We are very careful that a dress loaned to a star is not for sale," a guide told me. "A woman who buys Dior doesn't want to wear a dress she's already seen in public."

At stations throughout the upper floor of the building — which is normally used for fittings for exclusive clients — workers in white coats demonstrated the fine craft of tailoring a man's suit, making a woman's shoe and handbag (it takes 140 steps to assemble the Lady Dior bag), and molding the Bar jacket by hand to keep the collar standing high and the form shaped to the body. The jacket was so named because it was intended to be worn in a bar at a grand hotel during a late-afternoon cocktail hour.

In another area, workers embroidered sequined circles for an evening gown with painstaking detail. It takes 550 hours to embroider the circles in a single blue dress, and it's a wondrous sight to behold.

While showcasing a custom-made Baby Dior christening gown, where workers use a rare technique to twist each piece of lace, a guide turned the garment inside out to show the rarely seen handiwork.

"Christian Dior wanted the inside to be a beautiful as the outside," she said. The first collection for infants was launched next door at 28 Avenue Montaigne in 1967; the idea began 10 years earlier when Princess Grace of Monaco asked Dior to design a baby trousseau for the birth of her daughter Caroline.

In another room, workers show how a rose-shaped ring is made. It starts with a wax form that melts away, leaving a metal shape, where 600 small diamonds are added onto the petals with heat, not glue, to make them stick.

Then it was downstairs to the perfume area. There workers tied a ribbon onto each bottle of best-selling fragrances like Miss Dior (accented with a black ribbon) and J'adore (knotted with a golden thread after six precise turns).

"Christian Dior said perfume was the final touch of the dress, so that's why we put this at the end of the tour," our guide said.

Makes scents to me.