One of the most interesting place I visited in Morocco is the Leather Tannery of the imperial city of Fez. It's a one in a lifetime experience to see how men are busy producing leather whilst donkey are carrying the expensive good from one site to the other of the tannery. The smell is intense and locals give tourists mint leaves to fight the disgusting smell of the tannery. Pigeon faeces is used to soften the leather, that explains it all. :)Here are some pics of Fez, the tannery and the city itself. A must visit.