Complex sentence: Tafilalt or Tafilet is the most important oasis of the Moroccan Sahara, it is considered one of the largest oasis in the world; the oasis is ten days' journey south of Fez, across the Atlas.
Split into simpler sentences: Tafilalt or Tafilet is the most important oasis of the Moroccan Sahara, it is considered one of the largest oasis in the world. The oasis is ten days' journey south of Fez, across the Atlas.