One of Africa’s largest mosques and possibly the oldest university in the world, this mosque complex is the spiritual heart of Fez and Morocco itself. Established in 859 by Fatima el-Fihria, a Tunisian woman refugee, and expanded by the Almoravids in the 12th century, it can accommodate up to 20,000 people at prayer. It’s so large that it can be difficult to actually see: over the centuries the streets and houses of the Kairaouine quarter have encroached on the building so much they disguise its true shape. The complex has recently been restored, but non-Muslims cannot enter and will have to be content with glimpses of its courtyard from the main door on Derb Boutouil. Better still, take the view from any vantage point over the medina: the huge green pyramidal roof and minaret immediately announce their presence.