Ribat

A ribat is a small fortification enclosed by a wall, typically combining an entrance, living quarters, storehouses, a watchtower and, in larger examples, four to eight corner towers and a mosque. The form first appeared along the frontier of the early Muslim conquest of the Maghreb, built to house murabitun, volunteer soldiers guarding the border, and later spread along the frontier with the Byzantine Empire. Ribats served three overlapping roles, housing soldiers during the early conquests, functioning as caravanserais that protected trade routes, and operating as centers of piety for isolated Muslim communities. The Ribat of Monastir in Tunisia is among the surviving examples.