Kairouan (Arabic: القيروان Al Qairawān), also known as Kirwan or al-Qayrawan, is the capital of the Kairouan Governorate in Tunisia. Referred to as the Islamic Cultural Capital, it is a UNESCO World Heritage site. The city was founded by the Arabs around 670. In the period[citation needed] of Caliph Mu'awiya (reigned 661-680), it became an important centre for Islamic and Quranic learning, and thus attracting a large number of Muslims from various parts of the world, next only to Mecca and Medina. The holy Mosque of Uqba is situated in the city.[2][3] It is considered by many Muslims to be Islam's fourth holiest city.[4]