The Grand Mosque (Jamaa el-Kebir) is the oldest and most important building in Oujda's medina, founded in the late thirteenth century during the reign of the Marinid sultan Abu Yaqub Yusuf. The current building has been reworked over the centuries — the minaret is a nineteenth-century reconstruction — but elements of the original Marinid prayer hall survive, including the carved stucco around the mihrab.
Non-Muslims may not enter, but the building anchors the medina and the streets around it remain the busiest part of the old city. Friday mornings the surrounding lanes fill with worshippers.