Complex sentence: Since late antiquity Wargla was a stop for the Saharan trade, being along a caravan route of several thousand kilometers, going south from the Mediterranean to the Sahel and in the process crossing the great desert (Ar: aṣ-ṣaḥrā ´ al-kubra).
Split into simpler sentences: Since late antiquity Wargla was a stop for the Saharan trade, being situated along a caravan route of several thousand kilometers, stretching from the Mediterranean to the Sahel. In the process such caravans crossed the great desert (Ar: aṣ-ṣaḥrā ´ al-kubra).