Rather ambivalent experience - the tanneries are smelly and it can be hassling, too. They provide an interesting insight into the hard life of the tanners. It might change the way how you look at all the leather products in the shops.
Try to get on one of the balconies around – they offer the best views.
Address 118 Sidi Ghanem Akyoud - BP 3660 Marrakech 40000 Morocco
Coordinates 34°3'50.879" N -4°58'31.473" E