Marseille’s newest museum opened in 2018 to celebrate the city’s most famous industry: Savon de Marseille soap. The city’s official soap recipe was fixed in 1688 to feature 72 percent olive oil plus seawater and ashes. Bars bearing the stamp “72% extra pur” were exported worldwide and used by salty sailors on their voyages from Marseille, France’s most important port. Alongside a history lesson, a workshop allows customers to produce their own slab of bona-fide Marseille soap to take home. The temporary exhibition space opened with a “Bathroom of the Future” show, which highlighted a Japanese electronic toilet and an app that pours a bath—with not-so-subtle latherings of Savon de Marseille shown alongside.