The ancient walled city of Fez in Morocco is often compared to the similar structure of Jerusalem in design. Once the capital of Morocco in medieval times, this ancient city is a maze of roads and sights, but is well worth a trip. The Karourine Mosque is one example of 9th century architecture contrasted slightly with the newer New Fez of the 1500s.
Make sure to head to the Medina of Fez and the Gates of Fez to get an idea of the cultural history you are experiencing. Dar Batha Museum can also help. Fontaine Nejjarine is another beautiful picture for your camera. What you need to remember with Fez is that you will be pressured to hire on guides who are actually not licensed by the tourism bureau or government.
If you want to find a guide to lead you around, talk to your hotel or the tourism bureau for certified guides. The 'real' guides will not lead you to shops where you will be pressured to buy things at a higher price than you might find elsewhere.
Definitely make sure to bring a map - There are several great walking tours and they are well marked among the many alley-ways and streets of the medina - But one wrong turn and you can definitely get disorientated.
Fes-Saiss Airport is your final destination to get into this city directly, but you can also come from surrounding cities, like Casablanca, by car. The trip is about four hours, but the highways are in great shape, so they're easy to use for this kind of trip. You might also want to look into train options if you want to come from another area or buses are readily available for you to traverse the area. Getting through the narrow streets is tricky though, so you might want to find a way to travel the city on foot.
You can stay at a number of posh hotels like Riad Numero 9 or Dar Carboda, or you might like the inexpensive hostel scene: Dar Al Analous and Riad Tafilalet are just two choices you have.