The Roman Catholic cathedral is on Av Habib Bourguiba, outside the Medina. It dates to the time of the French occupation of Tunisia. It is a large late 19thC building with two towers and a central dome. It is built in a mixture of styles, including Moorish revival, Gothic revival, and Neo-Byzantine. Unusual for many catholic cathedral, it looks fairly plain inside. It is disliked by Lonely Planet and Rough Guide. I can’t say we particularly liked the architecture but it is an interesting building and there is plenty to admire.
The nave is massive with three aisles separated by columns with round topped arches. The walls and ceiling are painted white and the dark stonework of the pillars and arches stands out against them. Above is a narrow walkway with small balconies and a central cupola. There is a small screened side chapel for private prayer.
There is a decorative frieze of small stone round arches around the walls of the transepts and chancel. The arches in the choir area are more decorated. The dome in the choir has a painting of the Assumption of St Vincent de Paul with pictures of the Martyrs of Arbitina painted in the arches below. (I only know because there is writing underneath telling you.)
There is a free standing altar with a carving of the Madonna of Carthage and child behind it. A walkway round the back of the choir is decorated with mosaics of the saints on the walls and has a cage containing a descending spiral staircase. This is firmly locked.
There are a few statues in the church and stations of the cross on the walls. There is a confessional but no pulpit. There is a small decorative 19thC reliquary of King Louis IX of France.