Kairouan, 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 of Caliph Mu'awiya, 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. It is considered by many Muslims to be Islam's fourth holiest city.