The medina of Sfax is one of the largest and best-preserved in Tunisia, enclosed within its near-complete 9th-century Aghlabid walls. Unlike the medinas of Tunis or Sousse, it receives very few foreign tourists, which means it functions as a real working city: the lanes are crowded with shoppers, craftsmen, and residents going about their day rather than souvenir sellers catering to coaches.
The medina is roughly rectangular, about 700 metres across, and can be entered through several historic gates. The interior is divided into commercial zones — the souks for different trades cluster together as they have for centuries — and quieter residential quarters of whitewashed courtyard houses. Wandering without a specific destination is the best approach: the scale is manageable, it's difficult to get truly lost, and every lane has something to offer.