Wind towers are traditional architectural element very common in the Middle East. It actually serves to create natural ventilation in buildings.
According to my Arabic friends, the function of this tower is to catch cooler breeze that prevail at a higher level above the ground and to direct it into the interior of the buildings. Of course this was when air conditioning was not yet very common. Today wind towers are no longer a necessity however it is still incorporated in building designs to maintain the regions local identity.