I live in the Tunisian capital Tunis but my parents are originally from Sfax (economical capital).

The Medina there is unique It's different from tunisian medinas (like Tunis and Sousse).

It's still have the same lifestyle since centuries and architecturally speaking It's still intact :

- Its great beautiful wall which makes it the only islamic Medina that have a wall that's still complete and surrounds the whole ancient city or Medina

- Its great Mosque is still there in the center of the Medina

- the Activities there still authentic and not only touristic which makes this Medina unique comparing it to Tunis and Sousse

For example :  forgers in fonduk Haddadin and the leather workers in souk rabaa etc

- the tight roads inside the Medina are all perpendicular

 

The city still have the authenticity from centuries ago (it was founded since 1200 years in 849) and the wall is like a fortress that kept it unique

I think it should be a world heritage site due to its authenticity and the great state of its walls which makes the city look like a fortress from the outside