How did the first traders blaze caravan trails? Did they have camels already? Did the discovery of oasises or other settlements closely resemble the European age of discovery or did they have unique tools and capabilities? It seems remarkable that the traders could navigate a featureless area with so little resources or margin for error.
Are you talking about a particular geographic area? I don't normally associate caravan routes with a particular area, but it sounds like you could be talking about the Sahara or Arabian deserts.