Built in the 8C, the ribat in Monastir is the first of many monastery-fortresses which stand along the Mediterranean coast of Africa. Originally defensive forts built to withstand Christian invasions, as well as important centres of Islamic learning, these structures gradually lost their defensive role to become simple educational establishments. As a result, Monastir, "one of the gates to Paradise" according to the Prophet, became one of the leading intellectual and religious centres in Tunisia.