Mysteries in the Saudi desert

Leaning out of a helicopter's open door, 500 feet above the ground, David Kennedy is treated to bird's eye views of immense sand dunes and lava fields strewn with giant black domes and boulders. Among these natural wonders are mysterious triangular constructions, a beautifully preserved ghost town and elaborate ancient tombs -- the archaeological treasures which Saudi Arabia hopes will earn it a place on the heritage tourism map.