The 1884 French-built L'Acropolium is a Gothic extravaganza, an assertion of colonial power symbolically plonked in this historic location. It was dedicated to the 13th-century French saint-king Louis who died on the beach at Carthage in 1270 during the ill-fated Eighth Crusade (he was hoping to convert the Hafsid ruler, instead his troops wilted in the heat).
The deconsecrated cathedral's ice-cream interior has been restored and houses frequent, interesting exhibitions and concerts (hence the name change).