Mathilde Agostinelli >> Edgy �%lan: Paris.(France)

Byline: NATASHA FRASER-CAVASSONI editor: Sally Singer

When night falls, this fashion PR exec's hemlines--and youth factor--rise.

From London to Los Angeles, Milan to Mumbai, VOGUE toured eight cities around the globe to find the freshest takes on evening glamour.

Immaculate in black Prada pants and black V-neck sweater, Mathilde Agostinelli sips green tea and considers the state of big-night glamour in Paris. "If my friends and I have a goal now," she says, "it's to look nothing like our mothers."

Considering that mature Parisiennes famously look good, it's a strange remark. Yet such gathered wisdom of loyalty to personal style and subtle changes such as hair lightening with age are being shunned. "Our generation wants to look and stay as young as possible," Agostinelli notes. "Bourgeois is out, and anything that makes you look ladylike is verboten."

A major rewiring is going on. Certain mondain (social) Parisians--in their 30s and 40s--who by reputation were always chic, safe, and pretty ageless have become keen to be hip. "It's about dressing down in the most considered way possible," says Agostinelli.

Agostinelli's official title is Prada's press-and-public-relations manager, but she's also a major moteur in Parisian society. Underneath the Gigi-like laughter and what Lee Radziwill refers to as an "ooh-la-la" charm, she navigates many worlds. One night she might be in a strapless evening dress at a private ball thrown by the Aga Khan; another she'll be in a thigh-skimming Azzaro dining with French president Nicolas Sarkozy. Adding to her allure is her family's connection to fashion. Her sister is Victoire de Castellane, Dior's fine-jewelry creator; designer Gilles Dufour is her uncle.