Everyone in Monaco Looks Expensive, But Sofia Richie Grainge Outdid the Populace in This Black-Tie Gown

Nicknamed "the billionaire's playground," Monaco is one of the richest countries in the world when measured by GDP per capita. Smaller than NYC's Central Park, the tiny region is jam-packed with yachts, Michelin-starred restaurants, and luxury hotels. Residents of this tax haven love wearing the newest designer pieces, but Sofia Richie Grainge decided to take a different approach.

During a trip to Monaco, Richie Grainge wore an archival gown from Yves Saint Laurent's spring/summer 1979 collection. Yep, that means her 46-year-old dress is nearly double her age. On the runway, the gown was styled with a red coat, but Richie Grainge was wise to ditch the outerwear for her seaside summer night. Scroll down to see her new Instagram post, which has amassed over 100,000 likes in a matter of hours, and shop similar dresses for your next black-tie wedding.