Tanger has a lot of interesting places to visit, especially the mosques, which you will find everywhere in town. You can compare to Europe (or other parts of the world) where they having café’s in every street. Here you will find in almost every street a mosque. There are also lots of other things to see but I can’t remember the names or details again. It was only a one-day trip and it's so many years ago.
Asilah was unexpected. It was a time-killer on our trip, but has its charm. I understand that experienced do-it-yourself travellers can find decent accomodations here. It is 40 km from Tangier and could be a base from which to go to that city for day trips. (We have tips under the Asilah city name).