If you have a nomadic spirit, I can't recommend highly enough a stopover in Sidi Ali during your trip to Morocco. It's true that the site is beautiful, with the Mharech Pass only accessible in a 4x4 over a challenging track. And of course, with a good GPS: essential!
You can sometimes go several hours without seeing a living soul. The area is really very secluded. Despite several stays in the Moroccan Deep South, I must confess that for me, it was sometimes fairly disconcerting.
The main attraction is that you'll often have the feeling of being the king of the town: no queue on the horizon and if you stay in a riad (yes, you'll find some!) you'll be pampered like a star. But if the solitude is too much for you to bear, head to Rissani, the closest town, which is over 3 hours' drive away, all the same!