The "zaouia" is located on a street that bears the same name. Sidi Mehrez Ibn Khalef, « Patron of Tunis”, was born in Ariana (today a suburb north of Tunis) in the middle of the 4th H/10th c. AD. He was a devout Muslim known for his generosity. He spent his life teaching the Koran, hence his title of "al-muaddib" (teacher). Being Malekite, he defended this rite when the country was being ruled by the Fatimide dynasty who were Shia. He was also a defender of Jews and he did not hesitate to welcome them inside the Medina walls where they were allowed to live near his home in the neighbourhood of "al-Hara". The place where he used to teach became his resting place and a mausoleum. The sepulchre room has an oval dome sitting on four shells in sculptured stucco. The walls have coloured ceramic tiles on the lower part and naqch hadida and inscriptions on the upper part. The Tariqa Chadhouliya ritual is celebrated here by members of the brotherhood every Wednesday morning all year round except during the month of Ramadhan.