I reckon that the natural wonder that impacted me the most while visiting Morocco is without question the Sahara Desert. It is beautiful, it is intriguing, it is inspiring. The vastness of its great dune sea delighted me on a sensory level and it sort of mystified my soul. Standing there, engulfed by the harmonious yet hostile ecosystem I once again found myself asking "How? How? How?!" It is just so perfect. As William Langewiesche (author of Sahara Unveiled, a Journey Across the Desert) says, today there are very few places as huge and as wild, the Sahara is a difficult place to know. It might make a journey in and of itself, but for those who are travelling through Morocco it is totally worth even that superficial glimpse of its outskirts. Just observing the deep blue sky and the golden brown incredibly fine sand is a pleasure.
Here is the second article of the Moroccan series dedicated to this natural wonder: http://hubpages.com/hub/Sahara-Desert-a-highlight-in-Morocco