The wall of the mihrab is covered with 28 panels of white marble, carved and pierced, which have a wide variety of plant and geometric patterns including the stylised grape leaf, the flower and the shell. Behind the openwork hint, there is an oldest niche on which several assumptions were formulated. If one refers to the story of Al-Bakri, an Andalusian historian and geographer of the eleventh century, it is the mihrab which would be done by Uqba Ibn Nafi, the founder of Kairouan, whereas Lucien Golvin shares the view that it is not an old mihrab but hardly a begun construction which may serve to support marble panels and either goes back to work of Ziadet Allah I (817–838) or to those of Abul Ibrahim around the years 862–863. Above the marble cladding, the mihrab niche is crowned with a half dome-shaped vault made of manchineel bentwood. Covered with a thick coating completely painted, the concavity of the arch is decorated with intertwined scrolls enveloping stylised five-lobed vine leaves, three-lobed florets and sharp clusters, all in yellow on midnight blue background.