Located inside the 11th-century kasbah, this museum showcases an extraordinary collection of 2nd- and 3rd-century Roman mosaics, one of the best in the country. Most of these embellished the buildings in ancient Byzacium (Sousse and surrounds) and depict scenes from daily life – the fishing scenes are particularly charming. Highlights include a richly coloured mosaic of Neptune standing in his chariot, drawn by two hippocamps, and another depicting Bacchus, the Roman god of wine, riding in a satyr-driven chariot pulled by tigers.

　　Also notable are a mosaic of the head of an ocean god that originally decorated the Baths of Themetra at Chott Meriem near Sousse, two huge hunting mosaics in the rear gallery, and a Byzantine-era mosaic-covered baptismal font from El Gaalla, only excavated in 1993 and in excellent condition.

　　The multilingual labelling (Arabic, French and English) greatly enhances the visitor experience.

　　Note that there is no entrance from inside the medina walls.