The special feature of this tribe is that its lands are separated into two parts by a distance of 30 km. : Oulad Zyan Moualine el Oued southeast of Casablanca and Oulad Zyan Soualem south-west of the same city.
Bordered by the Ziaida tribe northeast by the Mdakra tribe southeast, by the Oulad Hariz tribe south-west by the Mediouna tribe northwest, and the Zenata tribe in the north. On his land, the river flows Oued el Maleh, it is also characterized by its many water sources (Ain Sbaa, Hlilifa Ain, Ain Zahra Ain Ghassalat, etc). Its territory stretches for 12 km along the Atlantic coast and separate Mediouna (Chaouia) and Chiadma (Doukkala).
According to Ibn Khaldun, the origin of Oulad Zyan is Arab, they are the descendants of Oulad Khalifa, their great grandfather is Zyan bin Khalifa bin Askar (which she kept the name) bin Nadir bin Urwa bin Zughba bin bin Abi Rabi bin Nahik of Banu Hilal, Arab tribe originating of Nejd (now a province of present Saudi Arabia) It therefore descend directly from the Prophet Muhammad.
- Mission Scientifique du Maroc (coll.), Villes et Tribus du Maroc: Casablanca et les Chaouïa, Ed. E. Leroux (Paris), 1915, Tome II, pp. 24-29
- Ibn khaldoun, Livre des exemples,considérations sur l’histoire des Arabes, des Persans et des Berbères
- L'historien et membre de l'Académie du Royaume du Maroc Abdelhadi Tazi