Meknes is a nice manageable sort of city located just a half hour by car or train from Fes. It was the capital of Morocco for about 50 years in the late 1600s and early 1700s during one of Morocco's boom periods. We stopped in for an afternoon on the way back to Fes from Volubilis. Except for one really really persistent kid we found Meknes to be hassle-free.
There are walls everywhere in Meknes, even more so than most Moroccan cities. Along with the walls around medina there is also an imperial city located just outside the medina which has its own walls. The palace section of the imperial city has some more, and then there are some nice wall extensions leading out of the medina in random directions, apparently just because they like walls.
We had read some really mixed reviews of the imperial city before arriving. The mausoleum of Moulay Ismail (who built much of this) draws most visitors sooner or later although non-Muslims can only view the tombs. Several sources we had read had nothing good to say about the imperial city but we found it rather engaging. The streets are similar to those in the medina but not as crowded. There's not a whole lot to do but it's a nice place to wander, and frankly, downright relaxing if you've been spending time in Fes.
Actually it was so deserted in the middle of the day that we didn't have any qualms taking a lot of pictures. The new city is across a bridge opposite the medina and imperial city. It looked to be fairly easy walking distance although we parked on the edge of the medina and proceeded to get lost inside (on purpose). There is one wide road separating the imperial city from the medina. It leads into a square where horse-drawn carriages hang out waiting for interested customers.
Just off of that is the vast open Place Hedim which looks like it could be the center of attention but wasn't. At least not the couple times we wandered through. At one end of the square is the enormous Bab Mansour (Conqueror's Gate). It's impressive and imposing but there's not much to do other than stand in the middle of this square and take a picture. After that you can turn around and visit the Jemai museum on the other side of the square as long as you haven't chosen to visit on a Tuesday.
We sat under an awning at a café and watched the square for a while. We really have no idea why this man came along and started inflating spider-man dolls in the middle of the square. Overall, we quite liked Meknes and if we were to plan this trip again it's entirely possible we'd base ourselves in Meknes and make the commute into Fes instead of the other way around.