Complex sentence: The town is located on a major desert route that would have facilitated trade betwen the Mediterranean and Mesopotamia (modern day Iraq and Saudi Arabia) and the history of the settlement dates from the Nabataean people who constructed the castle using the local basalt.
Split into simpler sentences: The town is located on a major desert route that would have facilitated trade within the region. The history of the settlement dates from the Nabataean people who constructed the castle using the local basalt.