Kairouan's mosque was partly assembled from other people's ruined buildings, and its minaret may be the oldest one still standing anywhere.
Columns with a previous life
The mosque's prayer hall is supported by a large number of reused spolia columns, capitals taken from earlier Roman and Byzantine structures across the region, no two entirely alike, a common practice in early Islamic architecture that here produced a forest of mismatched supports unified by the hall's roofline above them. The square minaret, built or substantially rebuilt in the eighth century, is widely cited as the oldest surviving minaret in the Islamic world, though the claim depends on how continuously rebuilt structures elsewhere are counted.
A founding legend involving buried gold
Tradition credits the Arab general Uqba ibn Nafi with founding both the city and its mosque in the seventh century, and local legend holds that a spring and a golden cup, previously lost, were miraculously revealed at the site he chose, linking the mosque's location to a story of divine confirmation rather than ordinary military convenience.
A ranking some claim, not all accept
Some traditions and local claims describe Kairouan's mosque as ranking fourth in sanctity within Islam after Mecca, Medina and Jerusalem, an honorific status promoted particularly within North African tradition rather than a designation universally recognised across the wider Muslim world.