Any suggestions as to routes in Morocco?

[willdew]

I'm going to Morocco for a week in September. Will be getting the ferry to Tangier, then heading down to Rabat, Casablanca, Marrakesh, Fes and back to Tangier. Any suggestions as to if there's any decent routes to make a detour to include? I'm thinking as we're around the Atlas mountains there's a chance there could be some decent roads in the area.