Kairouan is the holiest city in Tunisia, and the 4th holiest city in Islam after Mecca, Medina and Jerusalem. About 20,000 people pray in the interior square of the Great Mosque.
Kairouan is also the leading center of carpet-making in Tunisia, and somehow I wound up buying this silk, hand-knotted (1,000,000 knots per square meter) carpet shown below :)